Once you have completed the porting request process and received and entered the porting security code received by text message you can leave your Vodafone SIM in the phone if you want to continue using your existing number until it stops working and then insert your 48 SIM which should then work with your original number.
Or you can put the 48 SIM in immediately but it will only work with the new 089 number that it came with until your number has ported over.
It's up to you.
If you need to contact 48 support about this then see the links in my signature below.
