reset saved websitedata for others?

I don't really know what to ask for and if there is even a solution to it:

I have just recreated my own website so it's better looking and functional. I have taken down the htlm files of the old site and replaced them with the new ones..

When I reset my cookies n so on it works just perfectly but I have gotten my friends and family to test the website as well and some of them can still see the old sites or the links lead to nowhere and it seems like my site is not working as the browsers seem to prefere their memory instead of opening the now new excisting links..

I have been asking my friends to delete their cookies/website-memorie of their browser and the site works perfecly again...

Unfortunately I am unable to tell my customers so...

Is there a way to delete the memory or tell their browser to use the new data the browser receives instead of calling old/non existing links - from where I am ? As in a call inside the website telling the browser "hey I am new, use the new data"

That would just be awesome

Thanks again in advance

Chur

Anne