There's nothing scary in doing the work yourself and the tools are all dirt cheap from a good lbs - you don't need professional quality stuff.

Ride the bike into your lbs, tell them what it's doing, tell them you want to do the work yourself, ask them what you need.

Then ride home, fire up Park Tools AND Sheldon Brown and go from there. It's all stupidly straightforward but it's also not unusual to find yourself a little lost. Just read through the instructions again or ask daft questions here.

It is really really hard to break something so badly it's a disaster.

With a bike that old, you may find some bits are unwilling to come apart, if so, do what everyone else does and take the bit to your lbs to take off - have no shame or fear about that. If the shop knows you're trying to learn to do the stuff yourself, and the removal proved to be trivial (which is usually the case), a good lbs will do it on the spot for nothing.

Good shops are happy to work with home mechanics because they know you'll keep coming back for parts and tools and are more likely to maintain your bike than someone who puts it in for repairs when he can afford it. If your lbs doesn't support you in this, it's not a good shop and you should look somewhere else. Seriously.

Richard