Replacing the stove vent hood should be an easy thing to do. However I wanted it to vent inside in the winter and then vent outside in the summer. I also had to adapt from the new exhaust size of 7 inches to the old pipe size of 5 inches. I used a 7 inch to 6 inch adapter, then a 6 inch to 5 inch adapter. Then to shut off the external vent during the winter I added a 6 inch flapper. I had to cut off the old 5 inch pipe to make room for the new adapters. Then I had to cut 1 inch slots in the old 5 inch pipe to get the new adapter to fit inside of it.
I also had to cut bigger holes in the cupboard to fit the new 7 inch diameter pipe adapter. Then I had to cut it two more times to make room for everything to fit together.
Then I had to assemble the adapters with the closer/flapper and test it all out prior to installation.
This is what it looked like once assembled in the cupboard. The hole in the top of the cupboard is now closed off with duct tape. Cutting a piece of thin plywood to fit using a cardboard model would have looked better.
I forgot a picture of what it all looks like once assembled, hopefully I will include that soon.