Hi Karena,
I cannot really guide you towards a particular template, but what I would suggest is that you list the Rules for Annex VIII of the MDR in a table. Near each one, you identify which are applicable, and which are not, providing a rationale for each. You can obviously group many at once (e.g. you say it is not invasive, so rules 5-8 won't apply).
With respect to identifying whether it will qualify as 1r or not, again copy the definition of a reusable surgical instrument as provided in Annex VIII and provide your rationale as to why your product does not fit that definition.
If you haven't already, you're also supposed to provide a rationale as to why your product qualifies as a medical device under the MDR.
Hope this helps!