I noticed that the caulking around the tub is cracked and discolored with black slime (I'd post a photo, but I'm afraid of scaring sensitive board members - LOL). I am woman who's alone and getting up to being almost elderly and I've heard that doing this is easy and inexpensive. I've viewed Internet videos on how to do this, but it still seems overwhelming and confusing to me (the tub has to be dry where the caulk is to go and I don't think my tub is ever dry). One thing I haven't seen in the videos is what caulk to use (I'd probably want opaque white). Some videos say to remove the old caulk and some say you can re-caulk over the old. How can I get the edges of teh tub dry enough to apply the caulk? Any advice on this for an old lady?

I've done this many times for customers in the past. What I did was to use a single-edged razor to cut out the old caulk and scrape it really clean. If the old caulk was silicone, you then need to use a silicone remover to get it out. This will take some "elbow grease" and it may be more than you can handle.

You can use a hair blower to help dry it out, and it will need to be dry before continuing. If you use the tub every day, this could be a problem!

Then I would recaulk using a latex tub and tile adhesive caulk. It sets up pretty fast so don't go too far before you shape the caulk and clean up. I usually used a finger to shape the caulk but you can use a scrubber sponge instead. Then let that dry overnight.

You don't say where you are; I suggest putting it in your profile as I have done so we will know. I say that because if it is very humid in your location, doing this may take longer. For sure, leave the shower door open during the job. Realize that you will have to climb in the tub to do most of the work.

I think there is a less expensive way of doing this job...a good handyman should be able to complete this for you...and yes remove all the old calking and cleean well behind it and make sure it is dry.....use a blow dryer if necessary to dry the area where you are going to put in the new calking...however who ever does this for you make sure that the calking that they use is a MOLD RESISTANT CILICONE CALUKING....it is not too diffuclut of a job but getting the right size of an opening in your calking gun and travelling at the right speed can be tricky for one who has never done this type of work before....as soon as you put it on take your finger and use either siliva on the end of your finger or some cooking oil and a little water and smooth out your joint(long finger nails will not work for this) a tube of calking is under ten bucks where I live so if it dosesnt work for you its not a huge waste.

the tub is always wet ??
never completely dries out ??
remember, if it's wet BEHIND the caulk you just removed you may have discovered another problem..

I use GE silicone II caulk..
ready to use 4-6 hours after applying..

kick

Not to start an argument, but the latex caulk I use has a mold inhibitor built in. That is the tub and tile feature. The adhesive feature makes it more adhesive (figures!) and I find that alone makes it easier to use than any of the Silicone caulks. Silicone caulk is a lot more messy to work with than latex since it doesn't clean up well with water.

I have seen silicone caulks grow mold behind them, if clear. With the white silicone caulks, that mold usually becomes visible around the edges.

The silicone caulks don't adhere well IMHO; you can usually pick them out with a fingernail and they come out as a long rubbery strip. Unfortunately they leave a residue that is tough to remove, and even silicone will not stick to that. There are places where you must use a silicone caulk, but they are few and far between.

Must of the repair jobs I did for customers were where a silicone caulk had turned moldy or otherwise failed. I never had a call-back when using the right latex caulk.

A plummer recently showed me an interesting caulking technique. After he laid down a nice even bead of caulk, he sprayed the whole area liberally with Windex. Then he used his finger to shape the caulk. While the caulk was formed into a nice concave surface, the extra was easily lifted off without any sticking to the surrounding surface which was wet. Haven't tried it myself, but it sure looked like a good technique. Of course you could also do this with any kind of tool in place of a finger.

That interesting, I'll have to try it. I wonder if you slice the excess with a razor or at least to start it an peel it off.

I'd bet I have recaulked at least 400 tubs
I'll skip the details for now..

let's help the OP..
"should I hire a plumber"?
no

realize there is no X-ray vision in bath tile..
is it wallboard/tile ?
is it concrete/mesh/tile ?
once you take it apart you are committed..
a competent handyman can figure it out..

once again..
if you remove a few inches of caulk and it's wet behind the caulk....

let's diagnose first..
is this on the second floor ?

kick

He just wiped the excess off with a rag, while everything was still wet.

Yes, it's an upstairs bathroom. I live in upstate New York.