Changing couplers

[chartsmalm]

 
I just received a replacement loco with knuckle couplers installed , and with a packet of replacement Rapido couplers.

Eventually I want to change everything to the knuckle style, but everything I have now is Rapido. I have just spent the last 1/2 hour trying to find some help on how to make the change to Rapido. - with no result.

I know it's probably "duck soup" to the experienced hand  - but it is an absolute mystery to a newbie like me.

Can any one point me to an illustrated "how to" guide?

[ABC]

Here's all you need to do:
1. Remove coupler cover
2. Remove coupler and spring
3. Insert new coupler and spring
4. Replace coupler cover