[MISTERSCOOPS]

My passenger side door leaks when it rains and I’ve decided it needs to be lifted about 3mm
Got a suitable screwdriver, but the screws simply aren’t budging.
Looks like they’ve been painted over for a start.
I’ve sprayed a load of WD40 in there and will have another go on Monday when I got the new exhaust Centre box that I’ve discovered I need to buy on Monday morning

Any tips or suggestions on getting these screws to turn?

 

[tottot]

First get some RP90 or Plus Gas, WD is a rubbish release agent, its a water repellant.
The door screws are often pretty seized and need an impact driver to release.
A big correct size screwdriver assisted with vice grip on the shaft can shift some times.

 

[miktdish]

Impact driver and the super large/correct phillips head..

Buy some replacement J nuts and the correct bolts (they have countersunk heads).
Get the right length (or cut to fit) for the doors and use thin nylok nuts.

Amazon product

Here's a complete kit - bit OTT, but ...

Landrover Defender 90,110 A2 Stainless Steel 5 Door Bolt, Fittings+J Nuts Kit | eBay UK

Over 250 parts all in A2 Grade Stainless Steel. Surround screws. Kit contains:All exterior nuts bolts screws and washers over 260 parts for all 4 / 5 door vehicles. Front door bolts. 2nd row (passenger) door bolts.

www.ebay.co.uk

 

[meego]

Impact driver and the super large/correct phillips head..

Buy some replacement J nuts and the correct bolts (they have countersunk heads).
Get the right length (or cut to fit) for the doors and use thin nylok nuts.

Amazon product

Here's a complete kit - bit OTT, but ...

Landrover Defender 90,110 A2 Stainless Steel 5 Door Bolt, Fittings+J Nuts Kit | eBay UK

Over 250 parts all in A2 Grade Stainless Steel. Surround screws. Kit contains:All exterior nuts bolts screws and washers over 260 parts for all 4 / 5 door vehicles. Front door bolts. 2nd row (passenger) door bolts.

www.ebay.co.uk

+1 on new stainless steel fixings. And replace them on all of your doors.

 

[dag019]

+1 on new stainless steel fixings. And replace them on all of your doors.

^^ Another vote for this.
You will destroy your current ones removing them. The impact is likely to just pull the captive nut out of the pressed steel plate but it is worth a try. but some good quality drill bits to drill the head off is likely to be what you will need to do. Then replace with well greased stainless and you should not have the problem again.