Qhere is fuse for brake lights or park lightd

When this happens, usually it is because of a failure in the gearshift selector switch solenoid.
The gearshift selector solenoid is the switch that unlock the lever from park position when driver turns on the ignition and release brake pedal.
When brake pedal is depressed with selector in park position, this energizes the solenoid, unlocking the shifter.
Teh solenoid is energised by same circuit connecting the brake lights.
When for some reason (a short for example) the brake light fuse that protects the circuit blows, this will result in a failure to energize the solenoid, and lever won't be released from park position.
You find the fuse in the fuse box, on Discovery this is fuse number 1. This is a 15 Amps blue fuse. Fuse is located in the fascia fuse panel.
In most cases you fix the problem by replacing the brake light fuse.

Another reason for a failure to energize the solenoid is a faulty brake light switch.
This means the solenoid itself is faulty and need to be replaced.

How to proceed:

Check brake lights. If brake lights are not working, check and replace fuse number one in the fuse box. This will solve the problem in most cases.

If fuse keeps blowing there must be a short in the brake lights wiring.
You will need to access the rear light access panels and unplug the wiring harnesses that connects to the tail light assemblies.
Replace the fuse and try again to start the car, with all tail lights harnesses disconnected. If it starts drive the vehicle to the nearest mechanic, the vehicle will not be safe without tail and brake lights.

When fuse is not blowing check the brake light switch. Remove the panel above the brake pedal. There you find several switches, the second from the bottom will be the brake light switch. Unplug the switch connector, put parking brake on, turn on ignition and short the two green wired pins.
You should hear a click, while shorting the contacts move the shifter out of park position

When brake light are working fine, and lever stays on park position, it is usually the solenoid or its connections that are faulty. Try connecting directly the solenoid to power. The solenoid is connected to red and black wires. Apply 12 Volts across the wires, following polarity. If this worked the solenoid will click, and you will be able to move the gear out of parkposition. When there is no click you need to replace the faulty solenoid that is located in the shifter assembly.