First, if you have not already done so, you will have to register on your local council padron and get a padron certificate for a SIP card. You also now have to get your residence certificates as well.
Once you have the above, go to the social security office in Orihuela town with a interpreter if your spanish is not good enough.
Take with you, originals and copies of your passports, padron, residence cert. wedding license (if married) and possibly. because I am not sure and don't have any here, kids birth certs, e106 form.
If you have not been there, they have numbering system like the deli. counter at Sainsbury's, get a number, if the queue is long, a coffee. When your turn comes, give the person dealing with you the e106 forms, the padron and the residence certs. and whatever else they ask for. If they are in a good mood and your paperwork is in order they will stamp your e106 forms and that is it for now.
Now you have stamped e106 forms, go to your local Central de Salud (Health centre) at the times they deal with SIP cards, take with you, just in case, all what you took to Orihuela and also your E111 health cards you got from the uk. Hopefully you will walk away with temporary SIP cards dated until the end date of the e106 for the first year. They may only give you one for 6 months, if so, go back after the expiry date and they will give you another one for 6 months. A doctor will be alocated to you.
If you have 2 sets of e106 forms, keep the last set safe, as you will have to go through the whole procedure again the year after.
For the future, as long as Valencia do not carry out the threat to pull free health care, you may be able to continue to get temporary SIP cards once your e106 forms have run out. But don't rely on this fact.
Good luck