[DesertRatTom]

I always use a circular saw for this. I replaced all our interior doors a few years ago and I don't think the router is the tool for this. I would lay some green painter's tape over the cut line first to reduce chipout and splinters. It really helps.

 

[DesertRatTom]

I took the doors down and ran them through the table saw.

That works. Nice clean cut too.

 

[DesertRatTom]

Shortening the blade at home is not difficult with an electric jigsaw or circular saw.

Hi, glad you decided to jump into the Forum.

 

[DesertRatTom]

Detail. On exterior doors, if I trim them, I like to add a couple of coats of outdoor paint to the bottom edge so it's less likely to soak up water when it rains. I had to repair a church door that was in a low spot so water soaked the bottom and made it swell. Hard to close properly, a chore to fix.