Teach male to pee in center of pad.

Hi. Suggestions on how to teach a male to pee in center of wee-wee pad, please?

History: We had a male and female (neutered/spayed). Both did their "duties" outside during the day but use pads at night. The male would always pee on top of the female's pee which was in the center of the pad. Then our beloved Mia passed after 14 wonderful years. Now the male (also 14) pee on the edge of the pad and it always leaks outside making it more tedious to clen than before.