Hi Dave, like you we had the green Residencia card from years ago! We have just applied to change for TIE. We decided for ease to ask our Lawyer here to apply for us..( we use Susana Rosa near to La Piedra).
This is what we had to provide (which is slightly different from what it says on web site).
Valid passport
NEW Padron.....Susana obtained this for us.
Evidence of 3 months income into Spain...certified by Bank.
Evidence of 3 months account balance....certified by Bank.
Photocopy of SIP card...front and back.
Bank evidence of payment of TIE tax.
Form EX23 completed by Susana and she obtained the appointment.
One Passport type photograph. The background MUST be very white. We had professional ones done but were refused as background not white enough!!!! We had to find a machine and have further photos taken.
Susana met us at the Foreigners Office in Alicante and apart from photo.....it all went very well. We have paperwork to collect the TIE card in 4 weeks time in an office in Alicante. The staff were very pleasant....we did see a few people turned away because they did not have correct paperwork. So, again we thought it was money well spent to have been advised by Susana. The cost including TIE tax was 70 euros each.
Hope that helps. X