Need help figuring out the best way to fix this leak. Noticed a leak coming from the celing below the upstairs shower, only after someone took a shower. Seemed to drip for 20-30 minutes after the water was turned off then stop. I ended up pulling the celing down and discovering the set up I linked in the picture. It looks like the cold water copper supply is directly against the PVC drain trap and has over the years caused a small hole. What's my best course to fix a leak like this? Is this something that can be done with out disassembling the whole system? I'm a little above average do it yourself skill wise, am I out of my league on this one?
Picture of the set up and leak: