there is no update released for Nokia Asha 501. Not even a single update. Steps mentiioned above might me correct but as there is no update release you would not find any result from above steps.
You can update via PC suite or over the air which is mostly refered to as FOTA (updating software directly on phone) just go to Settings > Phone Updates > Download Software Updates.
Whilst FOTA instructions are correct end user cannot update Asha 501 using Nokia Suite on PC, although Nokia Care facilities have Nokia Software Updater for Retail for this purpose!
Happy to have helped forum in a small way with a Support Ratio = 37.0