Best way to change formula brands

[Slongette]

Travelling to South Africa for 3 weeks and can't get aptamil there but MIL has sourced hipp organic.

What is the best way to change from aptamil to hipp organic?

TIA

I would just switch tbh.

We switched between loads of brands (both powdered and pre-prepared ) all the time.

No problem at all.

Thanks - did not want tummy troubles whilst away so will just swop over when we've finished our current pot of aptamil.