Varnished skirts, now want satinwood. Best preperation?

[GaryMo]

We currently have softwood skirting boards, door frames and architraves which have been varnished to match the laminate flooring we have in three downstairs rooms.
Doors are hardwood with clear varnish but we'll probably leave them as they are.
It's now time for a change. We want to take up the laminate and revert back to carpets then paint the skirts, frames and architraves with white satinwood.

What would be the best preparation before coating with satinwood?

 

[Zampa]

The skirtings will need a really good rub down then a coat of a special primer like dulux super grip or zinseer bin.

 

[GaryMo]

Thanks Zampa