C squared - I think that teaching him to type proficiently is the first priority. If he has that handled, then I would move onto helping him with the handwriting.
What have you tried so far?
Things that help -
Any activity the increases strength and endurance - core so he can hold his body up, and fine motor.
Little rubbery things called 'pencil grippers' that go on the pencil to force the hand into proper position
'The Print tool' from Handwriting without tears - for him to analyse his own handwriting and see where he needs to focus his efforts. (assuming he is interested)
Smiles,
Grinity
