painting gloss over eggshell on woodwork

[foxboy]

I have previously painted doors, skirts and architraves in light green eggshell, which I want to gloss over in white.

How do I need to prepare the surfaces please..??

Should I sand down completely/slightly?
Do I need to use primer/undercoat?

Any help would be greatly appreciated

Thank you!

 

[Robbie uk]

Gentle rub down, sugar soap if required, one coat of undercoat and one coat of gloss paint.

 

[foxboy]

Champion! That sounds easy enough.. thanks Robbie!