Viessmann 100 plate heat exchanger removal

[Backbedroom]

Hello,
I have a Viessmann 100 WB1A (maybe 15 years old) and I want to remove and clean out the plate heat exchanger.
Its right at the back and I wondered if anyone knows if it can be removed simply by releasing the 2 bolts holding it in place, or does it need other stuff to be removed before it will come out?
Dropping it out of the bottom looked favourite, but there are too many pipes close up under the boiler.
There is one short copper pipe sticking up in the middle that does not look like it connects to anything, it seems to have a stop end at the top. See photo. The pipe is marked with the red arrow. I assume it could be removed by releasing the clip marked with the blue arrow. Would this leave enough jiggle room to get it out?
I don't mind draining the boiler and removing a couple of screws to get the plate out, but I don't want to get involved with any gas or serious disassembly.
I'm not gas registered, but competent enough to try and get the plate heat exchanger out.
If anyone has done this and has any tips it would be great.
Thanks.

 

[Backbedroom]

For the record in case anyone looks this up later.

It was impossible to remove the plate heat exchanger on this installation without first removing the clip and pipe arrowed in the photo.
Once removed, it was clear that the primary inlet of the heat exchanger was seriously clogged up with crispy black flakes of something.
These were quickly dissolved and loosened with several applications of "spirits of salt", flushed out with plenty of water and after about an hour we had a clean and well flowing heat exchanger.

Refitting was straight forward, but a couple things to look out for:
a) An inspection mirror was useful to check that the seals were still in place and that all traces of the black flakes had been removed from around the seals and mounting faces.
b) Try to align the protruding spigots on the heat exchanger with the holes for the bolts before trying to bring them together. If you are not careful, and the spigots go in the holes for the water instead and they can pull out a seal when you try to reposition the heat exchanger.

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DHW back to normal.