The Oasis Web Wallet is the best way to store and stake your ROSE:
A Chrome-based wallet with all the core features of the Oasis Web wallet in a compact Chrome extension:
The easiest way would be to create a new wallet with an Oasis Wallet and just transfer the tokens from your old Oasis account to a new Oasis account. The cost (i.e. transaction fee) should be negligible.If your tokens are staked/delegated, then you would need to debond them first which will take approximately 14 days. Then you would transfer them to a new account with an Oasis Wallet and stake/delegate them via an Oasis Wallet again.