Enable or disable a foreign key constraint.
ALTER TABLE dbo.TableName [NO]CHECK CONSTRAINT [FK_TableName_FTableName_IDColumn|ALL];
Enable or disable an index.
ALTER INDEX [IX_TableName_IndexName|ALL] ON dbo.TableName [DISABLE|REBUILD];
Recreate an index
CREATE INDEX IX_TableName_IndexName ON dbo.TableName(ColumnName) WITH ( DROP_EXISTING = ON );