Hi Allan,
AL-KO 1300 stabilisers were fitted to all Eriba Touring caravans, so it's a common(ish) topic on our Eriba forum.
Basically:
1. Look at each side of the AL-KO coupling head, you should see the pin-ends of the pads and a small (single use) clip on the end of the pin. Although it looks like circlip, it's actually a sprung steel split-ring that pops in-and-out of a groove in the pin.
2. Prise this split-ring off (two small screwdrivers are good), you will (probably) destroy it doing so - don't attempt this procedure unless you have the new pads and the new split-rings (part of the pad kit).
3. The pads then slide out into the centre of the coupling.
4. Fit new pads, remembering to apply a little smear of grease to the pins - so they can easily slide in the coupling head - do not get any grease on the pad surface.
5. Holding the pad in place, fit the new split-ring.
You may find a third-hand useful to hold the pad in place whilst you fit the new retaining split-ring.
You may find a large, black or dark coloured sheet or mat useful to catch the split-ring when it springs off the pin as you try to fit it.
It's an easy job, just take the usual precautions when doing any
mechanical work and check your work.
Robert