How do you get a bike into a van?

If you think you're going to put the bike in a van more than once, then a proper folding ramp is probably a better option.

As for getting it in there. Line bike up with ramp. Start engine and put in gear. With you standing along side the bike use the clutch and a bit of throttle to drive the bike up the ramp. When you get to the point where you need to step up into the van just stop the bike, step up, and continue. You just need to keep an eye on the wheel alignment with the ramp.

Getting it out is just a case of slowly easing the bike down the ramp using the front brake.

It is easier if you have someone else to help keep an eye on the wheels. But it's perfectly possible on your own.