Nissan Blaupunkt K12
It is quite simple to remove your Nissan Blaupunkt radio. You will need a set of radio release keys (PC5-83). These are inexpensive and are around £3, you can obtain them from Amazon.
Once you have the radio release keys, push them into the 4 holes in each corner of the radio (See image), apply a little pressure and the radio will release from the dashboard. The radios label will be located on the radio's casing.