if you want to display cached plans

SELECT cp.objtype AS PlanType,

OBJECT_NAME(st.objectid,st.dbid) AS ObjectName,

cp.refcounts AS ReferenceCounts,cp.usecounts AS UseCounts,

st.text AS SQLBatch,qp.query_plan AS QueryPlan

FROM sys.dm_exec_cached_plans AS cp

CROSS APPLY sys.dm_exec_query_plan(cp.plan_handle) AS qp

CROSS APPLY sys.dm_exec_sql_text(cp.plan_handle) AS st;

GO

To remove plans from cache memory

DBCC FREEPROCCACHE