If you want to recreate your temp tablespace, then follow below steps. For changing the default tablespace also, below steps can be used.

Find the existing temp tablespace details

Create another Temporary Tablespace TEMP1

Move Default Database temp tablespace

If any sessions are using temp space, then kill them.

Drop the original temp tablespace.

Drop temp tablespace

If you want to change the name from TEMP1 to TEMP, then follow the same process as below.

Create TEMP tablespace

Make TEMP as default tablespace

Drop temporary for tablespace temp1