SQLite Forum: How to reset auto increment on DB browser

Hello all i am trying my best to reset the auto-increment on DB browser but coming up with multiple santex errors, 

ALTER TABLE User AUTOINCREMENT = 1 

error log, 
ALTER TABLE User AUTOINCREMENT
-- Result: near "AUTOINCREMENT": syntax error
-- EXECUTING ALL IN 'SQL 1'



and 

SET @num :=0;

UPDATE User SET UserID = @num := (@num+1);

ALTER TABLE User AUTOINCREMENT = 1;

error log
SET
-- Result: near "SET": syntax error

i have no idea why its not working i done work with phpmyadmin on sqlitedbs 
and those both worked fine but for some reason i cant seem to reset the id number back to 1 from db browser if anyone knows how to do this could you please assist 

Kind Regards,
Elfenliedtopfan5