yea its REALLY hard to do with just yourself...i was trying it almost all day, then goto the ledge and slipped...its 100% easier with another person...yesterday, it was funny, a Airstrike came by the location, blew up everything, bins..crates..boxes...one got STUCK in the wall,lol-startyed making that annoying sound rattling abck in forth,i could use it to get to the roof top...u can try that, id say..percentage wise.tryiing to get to the top of the roof, 5% by yourself...60% by a forieng object getting stuck in that spot to boost u up, 101% when u use a friend or a body to jump on and jump on to the ledge then the roof..
now that people know that maps Steps/LEdge and cross beams,whats the name of that map?CRossFire? its the one with the Wrap around mosuliam...and gates and its kinda small desert map- but snce alot of ppl know about those good shooting spots ,good chance u can just wait for1 to sit there and shoot them b4 their body disappears...