A couple of things that you can try. First, make sure that you remain patient and don't get frustrated and too aggresive! With the left side pulled forward not more than 25mm, try to change the angle, tilting the top of the assembly down and/or up as you are pulling forward. Again, be gentle as you do not want to break anything. Each panel we have removed is slightly different. Some will come right out and others are a little more stubborn like yours!
If this doesn't work, you will need to remove the lower instrument panel (IP). (This is not as bad as it sounds!) Typically, the lower panel comes out relatively easily and you will likely need a helper to do it correctly. Start on the driver's side and pull up the weather strippinging the lower IP. Then you want to manuer your hands such that you can deliver a gentle yet sharp thrust toward you to pop the clips holding the IP in place. The whole trick is that you want to make sure that your are positioning your hands so that the sharp thrust is targetted at the clips and NOT where any energy will bend the IP. As soon as you get the first couple of clips (and they're the easiest over on the driver's side), you'll get the hang of it. Just go slow and careful and have a friend to help to support the panel. Immediately above the START button, the panel is only 25mm wide. Support this area well and NEVER let the panel bend here during the removal. This is mostly what the helper is for!
With the IP panel off, make sure that you have all of the metal clips attached to the IP and not still stuck in the dash or lower knee plate. If any are stuck, use a pair of needle nose pliars and remove them from the dash and then attach them to the corresponding tab on the IP you just removed. You may want to squeeze them with the pliars a bit so that the clips press on firmly to the IP. Now, remove the screws holding the lower metal plate in place. With these items removed, you can now get a few fingers behind the Speedometer and this will allow you the extra leverage to to push the back of the speedo forward.
I hope this helps. You can reply, email or PM me and I will help you. PM me and I will give you my cell number if you prefer to talk by phone.