Dashboard lights

[Newblet]

Hey, hope this is the right section.

I'm currently wanting to do some simple mods to my ford fiesta mk6.5 (56 reg) 1.25 style. I was wondering if anyone has a guide for changing the light color behind the Speedo.

 

I have read elsewhere that it's pretty simple to do but I am a little confused since they are old posts and images have expired.

 

Thanks in advance :-)

[Newblet]

Sorry to bump this but I didn't actually explain my issue. I can remove the dash and replace the bulbs but it's the filter I don't understand. Do I clean it with white spirit and put it back in or do I need to add anything to it since I cleaned off the green?