yup.. have done this myself to a set of older Judy DH's
just needs a larger hole drilling for the bolt and then some of the dropout carefully removing to allow the larger bolt head to sit properly..
you just need to be careful when drilling / filing that none of the material you are removing gets inside the fork legs..
if it does get inside the fork and you dont remove it it will eventually end up on one of the moving parts where it will form a lovely abrassive paste with the fork grease and kill your fork stanchions / bushing..