Unable to modify the form routine which is defined in implicit enhancement

HI Experts,

I am unable to change the form routine code. Please find my scenario below.

Implicit enhance ment has been created in include MV45AI0V_VBAP-VRKME_PRUEFEN

ENHANCEMENT 1 ZSD_RE_MENGEN_CHECK. "active version

• Prüfung Mengenfelder

PERFORM zz_re_mengen_check.

ENDENHANCEMENT.

form routine is defined in include MV45AFZZ,

form zz_re_mengen_check.

--> *I want to change the logic here

endform zz_re_mengen_check.

could you please provide me steps to change the code.

thanks in advance,

Mallareddy