First you switch to the thermal visor and you'll then see a piece of him glowing red, just lock on and blast away. After it takes a bit of damage your visor will be overloaded so switch back to the normal visor and you should be able to lock on to the part you were shooting before, shoot it till it's gone. Repeat above steps till he's dead
There's actually a really easy way to beat this boss. Take a look at the roof supports running diagonally and set out a little ways from the wall. There's a small horizontal piece at the back of some of these that you can stand on and still hit the boss. Best part is, being off the ground renders his earthquake attack useless, and you just have to worry about hitting the projectiles he throws at you.