Batteries Don't Fit Through Compartment Door; Cannot Replace

I like the posts that suggest AGM or some "maintenance free" solution. If OP can't get the batteries OUT, how can s/he check the electrolyte level? Our Jayco has clearance above the battery, but it sits in a deep tray, had to be tipped about 45* to pull out of the tray to set on the ground to check. Luckily, I was able to add drawer slides and can now bring it out level.