Hi, Simon
With a bit of a search I’ve unearthed the instructions for fitting said struts as supplied by MarkA
No pictures unfortunately butr perhaps with an advanced search you could probably find those.
Full fitting instructions
Parts required :
1 pair of struts
4 x 5mm nuts
4 x small washers
Tools required:
Measuring device (ruler)
Marking device (pencil)
2 x 8mm spanners
5mm drill bit
The Struts
Obviously you can do what you want with regard to buying struts but the parts I bought are as follows.
I bought them from RS Components. They are part number 182-4655 and cost approx �66 including VAT and delivery. They come with the ball connectors at each end but don’t come with nuts (I had some 5mm ones from B&Q in the garage already). If you buy/use different struts then the mounting points will be different (unless they are the same length, full technical details are on the RS site).
Fitting
First thing to do is loosen off the pressure in the struts, This is done using an allen key which comes with the struts, do it in one second bursts until you can push the struts down, but don’t soften off too much, also make sure you release the same pressure on the other one as well. DO NOT LET TOO MUCH OUT AS THE STRUTS CANNOT BE RE-PRESSURISED
Prop the cover up with your favourite bit of wood (for the last time ).
Onto the car, Firstly remove the 2 shiney black side panels in the engine bay (lower part) these are held in with one screw in the rain gulley and 2 plastic screws holding it to the main part at the rear window.
After this drill the relevant 5mm holes.
The hole on the plastic panel is positioned as follows. 95mm down from the point where the plastic panel meets the clam (under the rubber seal (see pics 2 & 3)) and 55mm from the rear window at that point (95mm down).
Position the strut in the hole and check the location point for the hole in the engine cover frame. It should be at the far end of the 2nd slot (furthest away from the hinge). This is on the inside edge (see the pictures). Moving it closer towards the engine cover hinge will mean it opens further, but it also means the struts may run out of travel before it is fully closed.
The 5mm holes will be quite tight to get the stud through but it will fit and it means there is less chance of it moving around.
The struts should be fitted with the body at the top (as per the instructions). Prior to fitting, make sure the pressure release grub screw will be easily accessable once the struts are fitted.
Getting the nuts on the end inside the engine cover frame is very fiddly (someone with small fingers is a bonus!).
Once all the nuts are fully tightened up try to close the cover. It probably won’t be possible, so begin to release the pressure further in the struts until it is possible to close with some pressure, If for any reason the struts run out of travel before you have fully closed the cover then you will need to lower the lower mounting point on the strut, this will also reduce the amount the cover opens. It is then down to personal preference to set the speed at which the cover opens, remember that if it’s too fast the abrupt stop when it reaches the fully open position could put undue stress on the mounting points which could lead to the panels cracking. Again DO NOT LET TOO MUCH OUT AS THE STRUTS CANNOT BE RE-PRESSURISED
Remember to refit the lower side panels.
This is how I fitted the parts on my car, if you mess it up or the usual quality Lotus tolerances mean your cover slots etc don’t match up IT ISN’T MY FAULT
Here endeth MarkA’s lesson . .
When checking to find this post, I was embarrassed to real;ise that it took me almost three years to get round to fitting them after buying.
Good luck.
the invoice went to the new owner but if you search the interweb for “strut regassing” you should find something …if I remember correctly caravan owners seem to need the service quite a lot…dont ask me why>��! 
(in joke for anyone who has done this job)