Turnip Boy Robs a Bank

So what I did was I went into settings, went to accessibility, turned on God Mode, and 3x damage. This allows you to make sure that you cause the most damage possible to get through the bosses, and God Mode ensures you never die

This achievement took me a long while and multiple attempts. At the end of the game you need to fight the 4 main bosses again and plant rockets where their bases are. Once finished you return to the courtyard and press the button for a cutscene and send the bank into space. Now for the final boss you must return to each of the 4 rockets and deactivate them, then return to the courtyard once again and press the button. The maps have been changed slightly and some don't connect to each other anymore. I've tried this boss over 10 times on xbox but it only took two attempts on the pc version (all game progress is synced to both console and pc).

Strategy:
What I did to beat the boss was use the assault rifle to fire directly infront of me at all times to quickly clear debris from that paths + kill enemies. From the courtyard I went to the right room, made my way down to the 4th boss rocket. Then I backtracked all the way up to the 3rd boss rocket. I backtracked the same route to return at the courtyard. From there I went down to the hallway and went right. After activating the 1st boss rocket I went straight up through the door in this room and made my way to the 2nd boss rocket. From there I backtracked through the park/forest area to the right back to the courtyard. You can pause the game at any time to stop the clock.

I apologies if my directions are fairly confusing, however this was the route I took to defeat the boss after many attempts. Goodluck

For those who prefer video guide: