How the experience outside the EASA environment can be justified?

Information on the experience required to obtain a license can be found in the “User Guide” (LIC-P66-P01-GU01), on the AESA website. 

Experience gained outside the EASA environment may be accepted provided that its authenticity is demonstrated, that it complies with the standards of Part 66 and is accredited in a manner acceptable to EASA. Such standards shall be similar to those of a Part 145 EASA maintenance facility. 

For this, in addition, the approval of the maintenance center in question issued by the local authority must be provided, as well as the appointment of the head of that center who signs the certificates.