You don't change your passphrase, you create a new wallet from a new passphrase and send there.

One variant for the steps are pretty well described in mk4 post.

I don't want to confuse you more, but it may worth considering Tails OS for the temporary wallet, since it's on USB stick with Electrum already installed (although it's not easy peasy if you're not computer savvy, you have to write down a temporary seed and keep in mind that's temporary, it would be wonderful to temporarily use the Tails as cold storage and there are a lot of transfers and reboots necessary).

On the other hand, if the funds are consistent and you're not computer savvy, the safest course of actions is to buy a second hardware wallet and transfer there. Of course, this time write down safely the seed.