Boot your system the press e to edit;

Change the ligne:

ro rhgb quiet 

to

 rw init=/sysroot/bin/sh 

Press ctrl + x to boot

From the root shell type:

chroot /sysroot 

Disable selinux

setenforce 0 

To change the root password type

passwd root 

Type your password twice . To change the user password:

passwd user 

Update the selenux file

touch /.autorelabel 

Type

exit reboot 

To update the selinux file , it will take a few minutes at:

relabeling could take a very long time depending on file 

then it will reboot

Boot your system the press e to edit grub;

Change the ligne:

ro rhgb quiet 

to

 rw init=/sysroot/bin/sh 

Press Ctrl + X to boot

From the root shell type:

chroot /sysroot 

Disable selinux

setenforce 0 

To change the root password type

passwd root 

Type your password twice . To change the user password:

passwd user 

Update the selenux file

touch /.autorelabel 

Type

exit reboot 

To update the selinux file , it will take a few minutes at:

relabeling could take a very long time depending on file 

then it will reboot