Front windshield wipers are crashing into each other

Yes you can adjust them yourself. First you need to check that the wiper arms are not bent. If not, remove the cap at the wiper arm base, under it u will find a nut, remove this nut. you should now be able to remove the wiper arm. (it is comon for caravan wiper arms to be corroded on. If the arm dosen't come off, you may need to heat up the wiper arm with a propane torch. be careful not to melt the plastic cowel under the arm. OR you can use a wiper puller or a battery puller. do not force it, you can break the arm, DO NOT PRY AGAINST THE COWEL OR WINDSHIELD.
Once both arms are off, turn your van on and turn the wipers on. watch the wiper posts, turn the wipers off and watch the wiper posts return and stop in the "parked" position. Turn the van off. Install the passanger wiper arm first, it is positioned closest to the bottom an inch or two above the black cowel. It should be parrallel to the cowel. next install the drivers side wiper arm. it is positioned about 4 inches above the passanger wiper. again running parrallel to the cowel and passanger wiper. tighten the lock nuts down (do not over tighten) wet down your windshield with glass cleaner or windshield washer fluid and test wipers. If they still hit you can lower the passanger one a little or raise the drivers one a little (careful you don't raise the drivers one too much or it will 'jump' off the windshield at the top of the wipe).
good luck, hope this helps.

The factory spec is 28" fr both blades, but some blade companies recommend a slightly shorter blade for the passenger side (26"). Do that.
That will fix it. Dont even need a wrench for this one.