SImply unbind the objects from their named cache. Then, bind the objects again back to their named cache. The "re-bind" step doesn't have to be done if we are talking about "default data cache".
For objects bound to named cache other than "default data cache":
exec sp_unbindcache <dbname>,<tablename>,<indexname>
exec sp_bindcache <cachename>,<dbname>,<tablename>,<indexname>
Now data will be read from disk on first retreival.
For "default data cache" objects:
exec sp_unbindcache <dbname>,<tablename>,<indexname>