I have a Skoda Fabia and need to change the tail lights.  I took the two screws out as per instructions but manual says I need a tool which is under wheel arch.  Can't find it and don't really understand it.  Can anyone help???

Take out the screws and gently pull the tail light out.
There are two plastic tabs which are hold by a clip which you need to pull out.
If you have those plastic removal tools it is way easier.

Hi - you might find the posts at the following thread helpful : 

 

 

The little metal tool you ask about is with the spare wheel kit. It’s also used for removing the cap to access the  towing eye. 

 

However - a plastic tool,  like those mentioned in above linked thread, will make the job much, much easier.