Next you need to remove the rubber boot surrounding the bottom of the shifter: look at previous pic. Be gentle with the boot, you will need to reuse it...:
When that is done wipe all grease away from the area so that you can see what you are doing.
You will then see the SPRING CLIP
that hold the shifter in place.
Take it out with the needle nose pliers.
Here is a pic of the clip, look close...