This will be a very costly procedure. First step will be to contact Piper and ask for any known available STC. If, and I doubt, there is an STC, next step will be to ask Piper for the costs involved in changing manuals for this particular aircraft.
Next step to follow is to contact the STC holder and enquire about the kit to be installed, costs, duration and, most important, acceptable workshops to accomplish the conversion.
If they have no particular electronic shop they work with, find one and be prepared that the STC holder will have to send a certifying engineer to be present during installation or, which is also a viable solution, to have a team from the STC holder to work in this e-shop and do the job.
The most important aspect for the local CAA is of course that you will ask them about the acceptancy of this STC and the costs involved.
Ahhh, I forgot, the local CAA will send you an invoice first before they will do anything....
The costs involved may easily accumulate to an amount which top the total value of the aircraft, think wisely before you invest into anything...
Good luck