The original font and rear MG logo badges were badly faded so I bought replacements. The rear badge is a replacement and old one needs to be removed. If you force a knife into the edge then you risk damaging the surround. The recommended method is to drill a small hole into the badge and screw in a screw to force the old badge out.
Once the old badge was out and placed next to the new badge the difference is very noticeable.
The front badge is different in that it is designed to stick over the original badge after making sure the surface is thoroughly cleaned. A lot easier job.
Update:- 8 months later the front badge came off! I didn’t realise that the original badge had a thin clear covering that eventually gave way. So I removed what was left of it, cleaned the surface, put some new adhesive tape on the badge and refixed it.
MG ZT info mods and maintenance 