You use 'remember' in the correct tense, that is, present if you remember now, past simple if you remembered in a given point in the past, or even the perfect tenses if you want...
Then you add the clause describing what you've remembered, again in the suitable tense.
Eg. You bought a car five years ago. You remember that you bought a car five years ago. Maybe it was yesterday that you remembered that you bought a car five years ago. But you may also remember that you had bought your son a car before that. You were planning to buy a new car, but hopefully you have remembered that you had bought one not long ago.
FRC