Since no one plays Conviction online anymore, I took my extra controller and signed it in as another profile on my Xbox, then played through the level by myself on realistic. (I'm a dork, I know.) I just had to get through the sections with Archer, then follow through with Kestrel.
If you're doing this the same way, the most difficult part was at the very end, where you have to take out the general. My advice for that is to have Archer set off an EMP and run to the first checkpoint, and stand there for a second until you get pointed to the next one. Set off your other EMP, then run over and hit it- it's just a big lever you have to pull. There's a place to hide in the wall behind the switch, get in there. Then you have to take Kestrel (who you left standing at the entrance) and use him to set off the other switch. It's important to also keep an eye out around Archer- if you're unlucky, the guards may have seen him get into that hiding spot. So hit that switch with Kestrel, then set off one of his EMPs and run over to Archer. Hide him in that little spot, and take out as many guards as you can. Eventually they'll stop coming, so now's your chance to shoot at the hanging container. Just move them both forward up that side until you have a clear shot at it. Line up their aims, then you can use one hand on each controller to fire away with their rifles. Once the container falls, send one guy back to the hiding spot, then use the other to head to the next checkpoint, keeping an eye out for straggler guards. You can take your point man all the way up to the dual lift area, then have him wait for the other.