What would be the best way to get my dog to the vet? hes a jack russel and very aggressive, fat and old?

Well its my Granny's dog and i think hes about 17? or 14, anyway old dog and does not get much exercise due to his nails being so big, we need to get his nails cut but he snaps and is very nervous dog , he was brought up in a farm if this helps, he lets the postmen in the garden and then goes for their ankles when they leave lol Mad dog, his nails actually crossed another 1 and he was in so much pain we can take it anymore so we need advice the best way to get him to vet, remember hes aggressive and wont go on a lead for a walk or anything