Awakened Spellbook, a level 3 Order of Scribes feature, says the following:
When you cast a wizard spell with a spell slot, you can temporarily replace its damage type with a type that appears in another spell in your spellbook, which magically alters the spell's formula for this casting only. The latter spell must be of the same level as the spell slot you expend.
If I cast a spell that deals multiple damage types, for example Ice Knife (https://www.dndbeyond.com/spells/ice-knife), how does this work? Could I change both damage types to a different type (for example force damage on initial hit, fire damage on burst) or only the same damage (force damage on both damage rolls). Also, could I switch the two damage types inside the spell, having cold damage on initial hit, and piercing damage on the burst?
Only the GM knows what happens when you try to change the damage type of a spell that deals multiple types of damage
Notably, the feature in question says that can replace its damage type, not its damage types. This works perfectly well for spells that only have one type of damage, but when there are spells like flame strike and ice knife and others, this becomes less clear. Strictly speaking those spells don't even have a damage type, they have multiple. Thus, under some sort of strict reading of the feature, it wouldn't work at all with these sorts of spells.
Instead, I would say it is undefined in this case and that any adjudication about what happens when you try the change the damage type of a spell that deals multiple types of damage is going to be left to the GM.