Level doesn't matter that much, considering you can do it while never getting out of your Skells. Just make sure everyone has beam weapons and Level 30 Skells, you have a G-Buster and Gravity damage-boosting skill, and target the dishes before the main body. It might also help to not concentrate fire, so that your party members can take out reinforcements while you dismantle the appendages.
Just stuff with beam damage since it gets bonuses against enemy skells and mechanical enemies. I used a BB-sword on my back slot and was practically one-shotting the enemy skells that appear every so often during that fight. So just load up on beam damage weapons and focus fire on the individual parts of the boss as they take more damage.
I have 3 BB Swords and 1 G Buster. I can see why they're good weapons.