Trimming bottom edge of internal door

[Robbox]

I have solid wood doors throughout and a couple need additional trimming after the carpets went in. Already painted, so I don't want to cause any edge breakage. I have a good circular saw and also a planer. Saw would be quickest, so how to knock off 5mm without damaging the painted edge? Masking tape?

 

[foxhole]

Saw, then plane at 45 degrees , finish with sandpaper.

 

[Robbox]

Does the tooth count on the saw blade make much difference to break-out?

 

[foxhole]

Does the tooth count on the saw blade make much difference to break-out?

Not enough to cause problem.

 

[HERTS P&D]

Score both sides with a marking gauge.

Andy

 

[Robbox]

All done and thanks for the advice everyone. Zero breakout as well!