There are generally two types of clips used. One is a spring type which just slides into holes in door and expands. Those can be pulled out from the outside by a wide stiff blade taped to protect the paint and slid under the strip. The other has a stud thru the hole with a nut inside the door. That type pulls the clip hard into strip and holds all to the door.
On the long straight pieces with rear side access there is usually a combination of the two. Spring for most with one or two of the stud type to tighten down and keep the strip from sliding.
Of course, if the strip has been removed and replaced before, there is any number of possibilities that could be there and almost requires looking to see what type and where.