how can i delete all of crawl errors in google webmaster tools ?

how can i delete all of crawl errors in google webmaster tools ?

 

You need to take a look which pages are having errors and what the errors exactly is. As example you can do a permanent redirect for 404 pages. Google will see it and will remove it automatically.

 

putting redirection for all those pages will make more burden on server.

 

Just 301 all those pages.

 

use 301 redirect to all