How to replace the shelf support bushing on siemens hb330550 oven?

Hi steve if its the ones I am thinking of you have square ish bushes in the side walls, note which ones are front and back they are different. To fit them they have spring steel clips on the other side of the oven wall, so its unplug, oven out, top panel off, one side panel off and fit bushes and clips then side back on, then ditto other side Cheers

Kenjo
June 2013