If you are replacing lifter you can use vise grip pliers and grip on outer shell and twist back and forth as you pull up to remove lifter
If you are just inspecting you would need hydraulic lifter removal tool as you don’t want to score the outside of lifer body
Here is Performance Tool #W84004
I agree with @60FlatTop when intake manifold is off and turn upside down and inspect expansion plug and replace it if any doubt Dorman products makes them
Bob
EDIT: I agree with @Aaron65 on cleaning your lifter