We are a little sloppy with our terminology.
For the most part, everyone knows what we mean, so nobody gets snooty about it.
But to be technical, what you have shown on those pictures:
1) is a big sheet metal mounting plate (with bent-up rim) which bolts to the ends of the LNB struts (arms)
2) the scalar ring is below that flat plate, and might work without being replaced - it has several wide deep groves in it
3) the feed horn proper which has the name Chaparral on it with:
3a) blue servo motor bolted to it
3b) some microwave plumbing / right angles / bolted to it
3c) the actual C-band LNB is mounted on the plumbing and has the coax connector.
So, what I'd do is pull the beer-can sized feed horn and all its attachments off your existing dish, and insert the
C2 in place.
If it doesn't fit in the 2..3 inch hole, you might need to change out the Chaparral scalar ring plate for the one shipped with the C2.
Obviously, care and alignment, as well as spacing and rotation will be need to be observed...
Hope I have supplied enough info for encouragement without insulting your intelligence. -
edit: and by all means save the material you remove.
I'm sure many of the members where would love to recycle some of your trash. - :up