The only DIY I know of on this is on Lextreme's site: http://www.lextreme.com/timing.htm
It's for a 2nd gen LS but there is a link to the first gen repair manual instructions. Using both of these you should have enough info to DIY
On a scale of 1-10 I would say that doing a timing belt change is either an 8 or a 9. I would consider a 10 to be a complete engine rebuild.