how to update supershop theme older version with Latest Version

Dear sir,

after one month i m checking my site and and here are some bugs and some module are also not working i checked that in one month supershop theme updated many time...
so how can i update latest version of supershop them with old version
i actually want to know the complete way how can i update latest version..
please let me how the easy way how can i update ur latest version in easy way

Thanks