It's quite simple, really...
If you're going to mail-order parts, you need to learn how to do your own maintenance. Use the money you save on parts and labor to buy the tools you need, and have at it. If you can turn a wrench clockwise and counterclockwise, you can install a bottom bracket.
A Park BB tool costs around $12. You'll need a crank puller too, if you don't already have one. That's ~ another $12-15. Use an 8mm allen wrench to remove the crank bolts, use the puller to remove the cranks. Then, starting on the left side (non-drive), insert the BB tool into the BB.
Assuming your bottom bracket spindle is hollow, use a rear quick-release skewer to hold the tool in place so it won't slip. This is optional, but will greatly reduce the risk of stripping the splines on the BB cups. Using a big box or crescent wrench (if you don't have one that fits, you can forego the skewer and use a socket wrench w/ the tool...just be CAREFUL not to let the tool slip), turn the left side cup counter-clockwise and remove it.
Repeat the process on the right (drive-side) cup BUT!!!!!! the drive side is threaded 'backwards'. This means you have to turn it CLOCKWISE to remove it and COUNTER-clockwise to re-install it.
Once you have the old BB out, clean the BB shell thoroughly with a rag, then lightly grease the threads on both the shell and the new BB cups. Carefully install the new BB by reversing the steps above (i.e. drive side first, counterclockwise, then the non-drive, clockwise. Tighten everything up well, but don't go crazy. You don't want to strip the threads on your frame.
That's all there is to it.
If you don't want to learn how to do it yourself, then you're probably better off paying the shop's retail price because a good shop will install the part for you for free.
Philo Beddoe said:
What is the deal on taking parts bought online to an LBS for install? I have a bottom braket and disc brakes that I would like to get put on. I would do the brakes myself but I don't want to mess with the BB.
I am thinking it would probably piss them off but I find that I usually settle for the parts they have in stock instead of what I really wanted to get when I deal with the LBS. I don't want to wait and pay premiums either.
Are they going to bang me on the cost to do the labor?