I used a paint stir stick to put my flat head against so I could gently pry. I ruined a pump housing AND a timing sprocket because of frustration before. If you use a brass hammer and gentle pressure you can slowly work if off

Richard E
1989 Montero - Stock-ish
1989 V6 Auto Raider - 5.3 Vortech Swap.
1987 Mitsubishi Starion 2.6t, soon to be 3.5
1983 Honda XL600R