I mainly want to focus on the melody and the song.. and I can't do the guitar solos with the piano especially if the guitar is a really weird not clear melody.

SO I want to skip that and just do the rest but when I play this song on the piano.. I want to make it a full complete song.. however since I'm going to be missing the solo and perhaps the ending etc then how do I make it a complete piece?

Its simple.. most people can't... you have to be a prodigy or have enough experience to be able to do it... but that takes a lot of time... unless you are a true prodigy you won't be able to... and they can do it naturally.