Welcome to the forums.

I know a guy who repairs Xbox 360's for a living and he has said that swapping disc trays is more hassle than it's worth (as you can pick up the classic Xbox 360's for around £60 now). Fixing the Red Ring of Death though is REALLY easy. It's literally a matter of taking the console apart, cleaning some thermal paste off and replacing the X Clamps with bolts and washers. It cost me less than £2 to repair one. I purchased a kit from here: http://bit.ly/h5BhB7 and it included all the pieces I needed, printed instructions and links to walkthroughs on how to do everything. If your console is out of warranty and you don't want to pay someone to do it for you, it is well worth it. The hardest part I found when fixing the Xbox 360 was taking the case apart. Applying the actual fix itself is easy.

Taking the console apart:

YouTube - How To Open An Xbox 360

Prepping the console for the XClamp fix:

YouTube - XBOX 360 Repair Guide - #2 Preparing for the X-Clamp Fix

Ignore part 3 of the video series about applying the fix if you buy the kit from the link I supplied, as their fix is slightly different (according to the email I received from them) but it is explained in the printed instructions you receive.

You're welcome. The sizes of the Torx screwdrivers that you will need is just the T8 and the T10. If you don't have any, you can pick them up on ebay for a couple of pounds.