That's the new thermostat fitted at long last. The problem was indeed additional mounting bolts holding the heat exchanger in place. One's a 13mm head and the other's a 6hex.
They are mounted to the back of the engine block and are most easily accessed by removing the EGR which is connected to the heat exchanger. They're to the right of the EGR and if you hold a small mirror round behind the back of the heat exchanger you should be able to find them.
With the EGR out and these two bolts undone the two bolts holding the thermostat can be undone. The top one's a 13mm bolt and easy enough. The bottom one had me stumped for ages but with the 10mm nut that holds the heat exchanger on the same bolt that holds the thermostat in place undone (and all of the connecting pipes undone, battery and box out, etc as well of course) you should be able to slip a 13mm socket spanner over the end and undo it. It will then come out and the new one can be fitted.
I can't make my mind up whether undoing the metal clamps that connect the metal pipes to the heat exchanger should be undone but if you do undo them watch for the small shims that are inside. Very easy to drop inside the engine.
They are mounted to the back of the engine block and are most easily accessed by removing the EGR which is connected to the heat exchanger. They're to the right of the EGR and if you hold a small mirror round behind the back of the heat exchanger you should be able to find them.
With the EGR out and these two bolts undone the two bolts holding the thermostat can be undone. The top one's a 13mm bolt and easy enough. The bottom one had me stumped for ages but with the 10mm nut that holds the heat exchanger on the same bolt that holds the thermostat in place undone (and all of the connecting pipes undone, battery and box out, etc as well of course) you should be able to slip a 13mm socket spanner over the end and undo it. It will then come out and the new one can be fitted.
I can't make my mind up whether undoing the metal clamps that connect the metal pipes to the heat exchanger should be undone but if you do undo them watch for the small shims that are inside. Very easy to drop inside the engine.