You cannot transfer the SIM card from a Galaxy A5 (2015) to a Grand Prime, because the A5 uses a nano SIM card and the Grand Prime uses a micro SIM card.
The nano card will not work in the Grand Prime.
If you wish to transfer the service to the other phone you’ll have to contact your phone service provider and get a new micro SIM card for your existing service.
Here’s a link to the user manual for a Galaxy A5 (2015)
Download it and then scroll to p.10-14 to view how to remove / insert the SIM tray and the SIM card etc.
Here’s a link to the user manual for a Galaxy grand Prime.
Download it and then scroll to p.10-12 to view how to remove / insert the SIM card etc.