need to reinstall final cut pro 6 but have a damaged install disc, what to do?

Are you trying to install FCP 6 on the Mac OS X10.7.5 system listed below your message?

That won't work unless you first install Rosetta from a Mac OS X 10.6 DVD.

If you pass that test and the disc really is physically damaged, you might try making a disk image of the DVD in Disk Utility. Use the DVD/CD Master format.

Obtaining a FCP 6 disc set will be difficult. Apple stopped making it years ago. Maybe used on eBay or Amazon.

do some googling on cleaning cd/dvd's.

Something like this?

http://www.bhphotovideo.com/c/product/419762-REG/Aleratec_240131_DVD_CD_Disc_Rep air_Plus.html

I bought a cd/dvd cleaner at radio shack years ago that saved my butt a number of times. Unfortunately, I have no idea where it is.

And Nick's right (like he usually is) that making a disk image and then mounting it, is a good first step to see if the physical dvd is the problem.