I just did that job. I laid on my back and cursed for hours!
Then it occurred to me: Take out the wiper motor!
It's bolted to the firewall with three bolts. One bolt holds the linkage to the inside of the motor.
Take out the wiper arm pivots from under the dash cowl. Use a long extension. They are bolted on with two bolts each.
If you're a big guy like me it's worth the effort to remove the front seat(s) so you can lay on your back.
Remove all the linkages and you can then rebuild all the linkages on the workbench and press on the bushings.
The finished completed unit with all three linkages and the swivels can easily be fished in under the dash through the wiper motor hole in the firewall and bolted back in to the upper cowl. (this is a great time to replace the gaskets on the swivels to keep water from leaking on your feet)
Here's some more notes from my job: The Dorman parts don't all work. I bought the Mopar replacements that were used on Dodge trucks and vans through the 80's
6 pcs Dodge Plymouth Chrysler Wiper Bushings Mopar A B C E Linkage Caps | eBay
As someone else suggested above, I pressed mine in by laying the linkage piece on a large socket (bigger than the grommet) and I used a socket extension (3/8" round end, I think) to insert into the grommet and tap it into place with a hammer. I think I used PB blaster as a lubricant. With the large socket underneath, it pops right through!
Again, I put all the linkages together on the bench and fished the completed assembly through the wiper motor hole.
Good Luck
