In this expansion there are two new quests. I don't understand how they can be used though. Could someone please explain to me whether or not they are replacements e.t.c.?

Thank You!

Every hero and monster collection, like the one you mentioned comes with 2 extra quests to play. They're not replacementes, just new quests to play, they don't beong to any specific campaign.

Specifically, these quests can be played as standalones (epic play rules) or can be incorporated into full campaigns as "rumor quests." Check out the rules for "manor of ravens" for rules on what to do with Rumor cards (which should have also come with the Oath of the Outcast Expansion.) If you don't have Lair, Trollfens, or Manor, you might not have many Rumor cards, since each hero and monster pack only includes 1. That's OK.

Well, this happened to me also. H&M Expansions does not bring any rules to tell you how to include and play rumors to the campaigns, they just say "incorporate to the Rumor Deck". So I had to look for the rules of any small expansion to know what to do. Here (page 7) you can see the rules for rumors.

[Edit: Here is the Manor of the Ravens' rules, page 5.]

Well, this happened to me also. H&M Expansions does not bring any rules to tell you how to include and play rumors to the campaigns, they just say "incorporate to the Rumor Deck". So I had to look for the rules of any small expansion to know what to do. Here (page 7) you can see the rules for rumors.

I recommend using the Manor of Ravens rulebook for reference instead. There was a change to the way Rumor quests work in an errata some time ago (particularly with what to do just before the interlude). The change was incorporated into the Manor rules, but Lair came out well before the change was made.

OK, thank you y'all!