Hi,

I was wondering if anyone could offer a novice diy'er some advice. My
letterbox was removed when our front door was painted; the bolt
receptor then got threaded while refitting it. The only letterbox I
could buy to replace it has *slightly* different dimensions, i.e.

1) The bolts are further apart.

2) The flap is a little bit too big for the old hole, and the spring
mechanism is larger.

Anyway, I'll need to resize the rectangular hole a few mm all round.
My questions a

1) What is the best way to make this hole a little bigger? Should I
use a chisel or a padsaw (I own neither so will have to buy one)?

2) Should I remove the door from its frame while I work on it? If so,
any tips?

3) If I can't get away with using the same bolt holes, I am planning
to glue some dowel into them, sand them down and then drill new holes
a few mm away. Will I need a particular type of wood glue for this?
Anything else I should bear in mind?

Any advice would be much appreciated.

Best regards,

Hamish