Not rocket surgery 

So many options, so little time (I say that as I sit here on the couch in a sling from shoulder surgery with nothing but time haha)

If your handy man can't figure out how to assemble them find someone else it's not rocket surgery!

I am guessing this is a plastic or fiberglass tub. 

Live and prepare yourself for the next bathroom reno, which you'll begin far more knowledgeable about the process and better prepared to do major surgery on your home?

If you do decide to install bars, you'll need to make sure it meets the state building code.There are bars you can put on the window railing. https://www.homedepot.com/p/Lock-it-Block-it-30-in-High-Impact-Plastic-White-Security-Burglar-Bar-and-Secondary-Window-Lock-2-Pack-LB-0001/206084100It's cheap, but I dont know if your tenant will be satisfied.

Sometimes it helps to dig the outside dirt next to the wall down a few feet and put in plastic so rain runoff doesn't seep in. 

Still, every so often, I fall back to my old training.For example, I had to consciously convince myself that the $750 I paid for melanoma surgery was a good thing... that I was happy to pay for it.

I do use Peroxide on paper towels with plastic over it to bleach out some of the staining.

Go to the big box and buy a roll of the heaviest plastic they sell, it should be 6 mil or thicker.