Unfortunately, shower heads are constructed differently. Removing the flow restrictor depends on the design. Sometimes, it's so easy you can pull them out with

Unfortunately, shower heads are constructed differently. Removing the flow restrictor depends on the design. Sometimes, it's so easy you can pull them out with a pair of pliers; other times, I've had to drill them out with a drill bit. They look like little metal or plastic screens, usually. In the US, all shower fixtures must come with them installed by regulation.