I just migrated my IOTA too and it's pretty simple. You just download the new firefly wallet for your pc and then you need to put in your IOTA seed from the trinity wallet and afterwards you will get a new 24 word recovery phrase shown that you need to write down of course because that is your new seed. Afterwards you need to type in those 24 words in the correct order to make sure you have wrote down the phrase as you should so it is pretty idiot proof i would say and does not take more than 10 minutes. You have time to migrate your IOTA until the big Coordicide update is coming which should not be before the end of this year.