The 8th Mission - Payback
This is not a hard mission but this video courtesy of 'Ryliesgames' shows you visually the exact route in case you got stuck at any point.
The video is on the PC but everything is exactly the same, the QTE's are randomly generated. Also the guy in the video doesn't know that you can change grenade type (if you have flares and 'nades) with up on the D-pad.
If you get stuck at some points its best to hang back and keep your gun pointed at the head height of the incoming infected and just mow them down from a safe position.
When you reach the mounted machine gun don't enter it, instead stand behind its outer sandbags with your back to the hut, one vault on your right and one on your left, the infected will get stuck on the small tower thing and you are safe in that area.