Try this code (I haven't tested).
DATA: BEGIN OF crhd OCCURS 0.
INCLUDE STRUCTURE crhd.
DATA:END OF crhd.
DATA: s_crhd TYPE crhd.
SELECT * FROM crhd INTO TABLE crhd WHERE arbpl = arbpl AND werks = werks.
LOOP AT crhd INTO s_crhd.
s_crhd-lvorm = 'X'.
MODIFY crhd FROM s_crhd TRANSPORTING lvorm.
CLEAR s_crhd.
ENDLOOP.
DATA: t_crca TYPE TABLE OF rcrca,
t_crco TYPE TABLE OF rcrco,
t_crtx TYPE TABLE OF rcrtx.
CALL FUNCTION 'CR_WORKCENTER_UPDATE_DIALOG'
EXPORTING
i_crhd = crhd
ukz = 'U'
TABLES
t_crca = t_crca
t_crco = t_crco
t_crtx = t_crtx.
COMMIT WORK.