Valve Guide Seals

Is it necessary to remove the motor to change valve guide seals or can it be done with the camshaft housing still installed.

Thanks in advance

It can be done with the motor in the car. There is a special valve spring compressor that compresses the spring from the 'outside'. You have to apply air pressure inside the cylinder via the spark plug fitting to keep the valve/s seated while you work on removing the spring and changing the stem seals. Not recommended if the real problem is guides.