Need education/advice on rebuilding telescopic main cylinder on Cat TC30 forklift.

I have a little cat tc30 fork lift. the main cylinder is drooling out the bottom and the forks drift down.

I cannot seem to locate any information on how to properly disassemble and reassemble the cylinder, much less service specs or anything like that.

I feel i have average mechanical ability, but no forklift experience at all.

The repair manual on ebay is 200 dollars, which puts it well out of my reach.