I've got oil leaking on the back push rod at the bottom (I think it's called the tapet cover) on my 05 EGC, TC88. I'm assuming there's a gasket under there. I can turn a wrench pretty good, but how difficult is it to replace it...and is that even the problem?

 

If its the lifter cover, the p-rods, tubes & lifters have to be removed then the cover removed to replace a gasket.
If you have adjustable p-rods...not that big of a deal if you know how to take them out & put back in.
If you have solid p-rods then the rocker box assembly has to be removed to get the p-rods out