Reaching exterior of cab over

I do it from a variety of methods.

1) 6' step-ladder and lean waaaaaaayyyyy over, all while trying not to put the ladder up on two legs. I am 6'-1" with a 36" sleeve length, so my proportions can sort of make this possible.

2) Via the RV ladder on the back, go up on the roof and lean over the "cliff". Don't do this if not fond of heights or dizziness comes easily.

3) A new trick I taught myself that works on the current he-man nose E-Series is to use the front bumper cut-out as a step-stool and stand in/on that. Again my long arms help to be able to get most of the front cap that way.

Lately I've been using some combo of the three.

I use a 2X12 plank clamped between 2 8' step ladders. Not as safe as a scaffold. But works with care. On mine a 12' long plank is required.

MobileBasset is right. A scaffold is probably the only way. And even with a scaffold, the area under the cabover is tricky to clean and wax.

Scaffold