Shrink TempDB Files

USE tempdb;
GO

-- 0. List files and sizes
SELECT file_id, name, size/128 AS CurrentSizeMB 
FROM sys.database_files;

-- 1. Flush dirty pages to disk
CHECKPOINT;
GO

-- 2. Clear cached execution plans holding tempdb object allocations
DBCC FREEPROCCACHE;
GO

-- 3. Clear tempdb system/buffer caches
DBCC FREESYSTEMCACHE ('tempdb');
GO
Immediately retry shrinking each file:

SQL
USE tempdb;
GO
DBCC SHRINKFILE (tempdev, 1024);
DBCC SHRINKFILE (temp2, 1024);
DBCC SHRINKFILE (temp3, 1024);
DBCC SHRINKFILE (temp4, 1024);
DBCC SHRINKFILE (temp5, 1024);
DBCC SHRINKFILE (temp6, 1024);
DBCC SHRINKFILE (temp7, 1024);
DBCC SHRINKFILE (temp8, 1024);
DBCC SHRINKFILE (templog, 1024);
GO