Do we need to shave the baby’s hair on the same day as the aqeeqah, and can we use a trimmer instead of a razor?

Assalam-u-alikum I am indian working in Germany.Alhamdulillah 3 weeks before we are blessed with Baby girl. We thought of doing the aqeeqah (slaughtering of animal) when we go to india in 2 -3 months. My question is do we need to shave the hair of the baby on the same day as aqeeqah or we can shave the hair now in germany and when we go back to india we can do the aqeeqah . Another question is that do we need to shave the hair using the raser/Blade or we can trim the hair with hair trimmer( with which some of the hair will be leftover) Jazakallh