hicks wrote:
I'm wondering, as it's such a small amount I need to remove, if
a plane is the right tool to use after all.

You could, but if you don't want a "schooldays experience",
make sure it's sharp! You can chamfer each side, and then
remove the central portion, which takes less effort than
going full width all the way:


| | | | |_________|
\_______| \_______/

1 2 3

Don't forget to plane "inwards" from each "edge" to avoid
the timber "breaking out"

You should be able to cut off 1/4" with a hand saw, though,
make sure it's sharp, and don't force it through, just let
it rub through with little pressure on it.

Apologies if you are already experienced...