Removing the SatNav on Mk4 Anni Gti??

[mk3 yeti]

Hey fellas, i know its not a passat but a bloke at work wants to take his headunit (with double din vw sat nav type) out to fit an ipod cable to the back, it appears to have 4 horizontal slots at the corners, i presume for the release keys, are these easy to get hold of?

thanks

Andy