Ehehe, loco's probably the easiest miniboss to kill on normal, imo (unless you count the run-in-circles condemned hunter, I guess). At least in my experience the only real trick is getting down hitting the thing, after that there's just... not much to it. 1st floor loco'll die to three unupgraded precision railgun shots, and it doesn't take much from the non-redshift mechs to drop either. The thing's kinda' ridiculously flimsy for all it's pretty quick. Don't really have to learn dodging or patterns or anything, just make sure you don't miss (much) and the fight won't last long enough for much else to matter. Don't be afraid to add some missiles into the mix, though. Even baseline ones'll chunk the thing pretty well.
So far as easy/later game stuff, just about anything homing will roll loco into a ball and stuff it down the drain. Want to say a large homing missile with the sac shop boost'll one shot the thing on like floor five, for example, and you don't have to do much but aim in its general direction and press the fire missile button, maybe even press it twice, heh. Maybe another one or two if you don't have appropriate damage buffs.
... but yeah, I don't have much advice besides hit the thing. Worry about aim more than getting hit and there's good odds you won't really get hit. Redshift takes like maybe ten seconds to drop loco on normal, and everything else doesn't really seem to take much longer, so I've never really learned its patterns or anything, heh. Spraying shots in its general path like ptarth mentioned works a'ight, too, since even fairly low accuracy'll drop it decently fast. I don't know if it can be overstated that for all loco is kinda' intimidating (flashy, noisy, pointy) and pretty fast, the thing's a paper tiger. Scary but flimsy and falls apart if you hit it with just about anything. Hit it before it can do much and it's not a problem.
