Do you mean TRE?
You do not need a seminar to revalidate or renew your TRI -(2) Helicopters and powered lift
To revalidate a TRI (H) or TRI(PL) certificate, applicants shall, within the validity period of the TRI certificate fulfil at least two out of the three following requirements:
(i) completed at least 50 hours of flight instruction in each of the types of aircraft for which instructional privileges are held or in an FSTD representing those types, of which at least 15 hours shall be completed in the period of 12 months immediately preceding the expiry date of the TRI certificate. In the case of a TRI(PL), those hours shall be completed as a TRI or a type rating examiner (TRE), or as an SFI or a synthetic flight examiner (SFE). In the case of a TRI(H), the time flown as FIs, instrument rating instructors (IRIs), synthetic training instructors (STIs) or as any kind of examiners shall be accounted for this purpose
(ii) complete instructor refresher training as a TRI(H) or TRI(PL), as relevant, at an ATO;
(iii) in the period of 12 months immediately preceding the expiry date of the certificate, passed an assessment of competence in accordance with points FCL.935, FCL.910.TRI(b)(3) or FCL.910.TRI(c)(3), as applicable.
(3) For at least each alternate revalidation of a TRI certificate, holders shall pass the assessment of competence in accordance with point FCL.935.
(4) If TRIs hold a certificate for more than one type of aircraft within the same category, the assessment of competence taken on one of those types of aircraft shall revalidate the TRI certificate for the other types held within the same category of aircraft, unless it is otherwise determined in the OSD.
(5) Specific requirements for the revalidation of a TRI(H) certificate
TRIs(H) holding an FI(H) certificate in the relevant type shall be deemed to comply with the requirements in point (a). In that case, the TRI(H) certificate shall be valid until the expiry date of the FI(H) certificate.
(b) Renewal
To renew a TRI certificate, applicants shall, within the 12 months immediately preceding the date of the application, have passed the assessment of competence in accordance with point FCL.935 and shall have completed the following
(2) for helicopters and powered lift:
(i) at least 10 hours of flight time, including take-offs and landings on the applicable aircraft type, of which maximum 5 hours may be completed in an FFS or FTD 2/3;
(ii) instructor refresher training as a TRI at an ATO, which shall cover the relevant elements of the TRI training course.