It's somewhat straightforward but I recall them being riveted together so will require a new rivet or screw in the lower frame rail.
Here are some sites/info; that may be of help.
1967 Fisher Body Manual.
A-Body Vent window info; starts on Pg 6-45
http://www.thefirstgensite.com/libra...67S6P22_86.pdf
This is a decent write up at Hagerty.
More about the glass replacement but may offer some help.
http://www.hagerty.com/articles-vide...ss-Replacement.
I don't have any loose vent window frame assemblies on hand but may be able to offer any assist with ones on the cars.
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When I die, I want to go peacefully like my grandfather did, in his sleep.
Not screaming like the passengers in his car.
