Which model have you got? I’m not sure on the differences between the 156/200 or diesel (topside) but on my 156 If you remove your brake fluid reservoir (two T20) then pull it out (quite a bit) and across over to the right over the battery cover and shine a torch directly behind it you can see the bleed nipple on the heater hose going into the bulkhead
I’ve managed to bleed both my bleed screws just moving the brake fluid reservoir
The thermostat bleed screw is accessible if you shine a light directly down you can just see the top and will need a long screwdriver at a particular angle to access, if I get a chance tomorrow I’ll take a pic of the screwdriver seated
Practise first on a cold engine feeding your hand through blind onto the nipple and just turning (without turning) quarter and back out shine torch and check, keep doing this till you know the route
With engine upto temp and after doing the thermostat the heater hose nipple is quite straightforward
I did it in short sleeves but put some long sleeves on if you don’t feel comfortable jamming your arm in there. Again this is on a 156 right hand drive and was straightforward