For this fight you will want to equip an armor set with high fire resistance. I went with the Gaia set. Upgrade as much as you can. The choice of implants is also critical, I went with Rig Capaciitor XL (essential), Energy Dynamo (energy gain is essential), I then went with implants which boosted health mainly to get me through phase 2, so Battery Auto Healer, Decharge Regenerator. I also recommend a fast attack weapon such as Gaia Lancer. I was level 60, however having the correct equipment and tactics is essential.
Phase 1
Target his legs and destroy the armor on each leg. Get as close as possible and try to stay behind him, pound him as much as possible. As soon as the armor on 1 leg is gone, target the other. Watch out for the ground turning an orange color, as soon as you see this, evade away, then look for a container to hide behind. Once his attack has finished get back in there. As soon as the leg armor is destroyed you can do massive damage to him.
Phase 1 just takes practice but you will quickly be able to get through this phase most times, phase 2 however is a different story
Phase 2
Not only do you have the General to deal with but you also have his Machine constantly firing.
Immediately run to the opposite side of the area and stay close to the walls, never stand still as the machine rains down rockets. I targeted the generals right arm to get a special weapon. If you maintain a distance from him you can bait him into an unblockable jumping attack, when you see him about to do this attack, wait until he is just about to jump then jump out of the way by pushing in the Left Stick. While he is recovering hit him with an RT attack then immediately spam the RB attack, you should perform the Special spinning attack (if you have a different style weapon equipped make sure you use that weapons combo attack. I used the GAIA weapon). As soon as your attack is finished get out of there, again stay near a wall and try and bait that jump attack.
Never try and be to greedy, hit him a few times, then back off, try and bait his jumping attack and pounce with the heavy hits. Listen for his machine you can hear when he is about to rain down rocket attacks, but as long as you stay moving, bait the jump attack and use the RT attack followed by RB you will quickly get his health down.
Always try and keep 1 battery spare for desparate times, implants which boost energy gain and prevent battery decay are essential. Phase 2 is the hardest phase, it will take time but you will learn the movements and animations and slowly improve each time. Don't Give Up