Installation instructions for p2pool (both jtoomimnet and mainnet) can be found in the second post of this thread:

https://forum.bitcoin.com/pools/p2pool-decentralized-dos-resistant-trustless-censorship-resistant-pool-t69932.html

I recommend that all subsequent discussion of p2pool be done in that thread, as it seems that the majority of p2pool-related discussion is now being considered off-topic in this thread. That forum's software is better, too.