Locking queries

How can I found which user has locked the tables and is it possible to release the lock by other users? Please provide me T-SQL query to get the lock details and How can I release it?



I got this query
Locking queries
1->select * from sys.sysprocesses Where SPID=65--and Open_Tran>0



2->SP_LOCK

3->SELECT
t1.resource_type,
t1.resource_database_id,
t1.resource_associated_entity_id,
t1.request_mode,
t1.request_session_id,
t2.blocking_session_id,
o1.name 'object name',
o1.type_desc 'object descr',
p1.partition_id 'partition id',
p1.rows 'partition/page rows',
a1.type_desc 'index descr',
a1.container_id 'index/page container_id'
FROM sys.dm_tran_locks as t1 INNER JOIN sys.dm_os_waiting_tasks as t2 ON t1.lock_owner_address = t2.resource_address
LEFT OUTER JOIN sys.objects o1 on o1.object_id = t1.resource_associated_entity_id
LEFT OUTER JOIN sys.partitions p1 on p1.hobt_id = t1.resource_associated_entity_id
LEFT OUTER JOIN sys.allocation_units a1 on a1.allocation_unit_id = t1.resource_associated_entity_id