Hi all,
Well i bit the bullet and opened up the RH450 to carry out the repairs and guess what, it was a real nightmare...... no not really it was really easy to do, here are some photos and a guide, i hope it helps anyone trying to do the same:
Tools required:
Allen key set
Torx bit set (got mine from screw fix £5.99)
Screw driver (pozi drive small)
1: First you need to remove the 3 torx bit screws on the top and the bottom of the unit. you also need to remove the rotary knobs from the front, these simple pull off, just pull square and with medium force to remove, i did not need to wobble them.
[attachment=134971:IMG_0425.JPG]
2: Then you need to remove the screws on the bottom of the unit (all of them), you will also need to remove the sticker as one is hiding under it, you do not need to remove the feet these can stay where they are.
[attachment=134972:IMG_0424.JPG]
3: You can now slide the casing off to the left, do this gently as the plastic front control panel sits in a channel on the casting.
[attachment=134973:IMG_0422.JPG]
4: You now need to remove the 2 allen key bolts in the black metal vented section on the right.
[attachment=134974:IMG_0423.JPG]
[attachment=134975:IMG_0414.JPG]
5: Now the front plastic panel can be removed.
[attachment=134976:IMG_0415.JPG]
[attachment=134977:IMG_0416.JPG]
6: The Memory buttons and shift buttons can be pulled off very easy and replaced now.
[attachment=134978:IMG_0419.JPG]
[attachment=134979:IMG_0420.JPG]
7: Once replaced put front panel back on, it is not glued in any way so easy to remove and replace. Then refit the black vented metal section and then refit the main casing and refit all of the screws removed.
[attachment=134980:IMG_0421.JPG]
[attachment=134981:IMG_0422.JPG]
8: The last thing to do is just push on the replacement Knobs, if yours were not broken like mine to start with then you can refit the ones you pulled off at the start, if you were careful they will not have broken.
[attachment=134982:IMG_0426.JPG]
There we go good as new and only took 30 mins start to finish.
[attachment=134984:IMG_0428.JPG]
Hope this helps
Big Rob