You should have the filtere pressed into the body of the water unit under the brass cap (the one visible in the photo below).
After unscrewing, gently release the water shut-off valve to the stove so that something from the tube may still come out.
Remove the filterer from the body (use a screwdriver, only carefully so as not to damage the strainers), clean and fold.
In addition, check the aerators in the taps if they are, although you write that the problem is only with hot water pressure, so it should be ok.