How can I get a Special Certificate for Experimental Flights from RPAS?

Procedure information and form on the AESA E-Office website: 

https://sede.seguridadaerea.gob.es/sede-aesa/catalogo-de-procedimientos/certificado-especial-para-vuelos-experimentales

For electronic submission, the General Application procedure must be used (on the same page, in the link to electronic procedures). 
 
Please indicate in the text that you are directed to the attention of the Initial Airworthiness Division.