Hi Callum,
You could but I would give it a go if I was you.
My ones looked very very corroded and rusty, (that horrible deep red heat baked type of corrosion) I was very hesitant to give it a go.
heres the advice i was given and what i did.
give them a going over with a brush then a thorough soaking in penetrating fluid (I prefer plusgas, but wd40 should do it) the night before. Next day give them another soaking, (obviously don't start engine between soakings) then just make sure the tool you are using is seated nice and snug (light tap with hammer) get your one had on head of ratchet to make sure it stays straight and true and other hand on handle undo the bolt.
My TD5 is an 03 with 123K on the clock, they came out just fine, made some strange squeaks and groans but all good, came out just fine, once out give the holes a squirt before popping in the new ones for the blanking plate, the main problem is that people don't use the tools properly, don't seat the bit correctly, pull at an odd angle then round of the inside of the bolt.
Once job is done,
Start engine with bonnet up and warm up, you will get odd smells and bit of smoke as the penetrating fluid evaporates and the silicone cures, gently increase revs to warm up but don't go mad, when smell and smoking stops job done!
Dont forget to disconnect power leads to the solenoids, no need for them to be using current anymore!
Use Locktite 5990 (copper silicone) to seal blanking plate, its only £6 halfords.