If I understand correctly. I have to take off the oil filter and then ?turn? The engine if they are not upwards symetrically.
Excuse me when I describe things not detailledly enough, but I only begin to understand that you are still learning and some details are still new to you.
YES, the timing belt cover has to be removed! (green circle in your picture)
First let me know if your engine is a 2.000cm³ OHC as a 1300 or 1600cm³ Engine can be damaged considerably when the timing belt is installed incorrectly and the engine is cranked !!
If you have a 2.000cm³ engine:
The gearbox must be in idle position. The engine is being turned then bei putting a ring spanner or ratchet on the 19mm Hex Head screw in the centre of the crank pulley.
Never turn it anti-clockwise and / or on any other screws, e.g. on the camshaft pulley! This might damage the toothed timing belt and other parts of the engine.
You can turn the engine a lot easier when removing the spark plugs first, but I understood that two of them seem to be seized ...
So the "business" is to bring the engine in this position:
If it is impossible to bring the engine into the position shown the toothed timing belt may not be installed correctly.
Please try this and if it doesn't work we have to rectify that first ... do not start the engine then!!
Please remove the 19mm spanner every time you do not turn your engine !!