This sounds a bit like a generic homework assignment ..... so here's a generic answer
1) Copy records older than 6 months into archive tables.
insert into Archive_table select * from Prod_table
where Archive_date < DATEADD(MONTH, -6, (getdate()))
2) Delete records older than 6 months from production tables.
delete from Prod_table
where Archive_date < DATEADD(MONTH, -6, (getdate()))
3) Change your stored procedures to point to the archive tables.