Thicken some lines on autocad.

I know a similar thread already is, but mine is a little different. I have made a project on autocad and now i need some of the lines to be thicker and some of them thinner. When i select the llines i want thicker and go to lineweight settings, set the preferred thickness it applies that to all of the lines.. How do i do what i want? Thank you in advance! Have a nice day!

Already sorted that out.

1.) Select the lines you needs thicken.

2.) Hit the Ctrl + 1

3.) Under general, modify the thickness.