(sorry: the third command shouldn't appear at all, the fourth command is wrong: it should be "mkdir /lib/modules/2.6.20-12-generic/extra", not "mkdir cd /lib/modules/2.6.20-12-generic/extra")
(sorry: the third command shouldn't appear at all, the fourth command is wrong: it should be "mkdir /lib/modules/ 2.6.20- 12-generic/ extra", not "mkdir cd /lib/modules/ 2.6.20- 12-generic/ extra")