FitzTheRuke
Legend
While it may be true that cantrips are known, it's also true that we have a cool, laid back DM. He might let you swap something out for it anyway (like Mending), or maybe allow a cantrip exchange when you hit a new level. Unless, of course, you don't want Toll the Dead. I'm not trying to force it on you. I just figured you might enjoy having a second ranged damage option that targets a different save and hits a bit harder.
I absolutely would allow it, I've always been easy-going that way. While I'm not a fan of opped-up characters, I like players to be happy with what they're playing. If it feels weird to swap mid-stride, wait until level-up, but I'm not super picky if you want it now. (In particular if you come up with a little story on how Lathander granted it in his time of need - also, maybe reflavour it just a little to Lathander it up a bit)
Let me know what you want to do!