You may need to remove the door to do this, but plane the edge where it is sticking and redecorate the bare timber as soon as possible.
Efallai y bydd angen i chi dynnu'r drws o'r ffrâm i wneud hyn, ond plaeniwch yr ymyl sy'n mynd yn sownd ac ailaddurnwch y pren noeth cyn gynted â phosibl.