deleting SXMSCLUP and SXMSCLUR / Quesiton on DEL flag in SXMSPMAST

1) how can we delete entries out of these tables?

2) I defined retention periods and since then the msgs are being flagged for ARCH but the older msgs which were in the system before i defined retention period and scheduled the archiving and deletion jobs, are now marked with status DEL in SXMSPMAST.

Can someone help me on this on how to delete old msgs in the tables?