Couple of things you can try:
-
Clear composer cache
$ composer clear-cache -
Remove any valet global files from composer
$ rm -rf ~/.config/composer/vendor/laravel/valet
Note I am in linux so your composer global path might be different. If you don't know where the global composer folder is located try running
$ composer global update
And hit CTRL+C to stop the update. The first line in the output must be something like:
Changed current directory to /home/rodrigo/.config/composer
That is where your composer global files are located.
One alternative to manually removing the valet files would be trying to remove it globally:
$ composer global remove laravel/valet
Hope any of this helps you.