Hearthpwn

i dont have Lady Liadrin and Lynessa Sunsorrow.... replacements?

I would probably not play this deck at that point, you at least one to close a lot of matchups out such as razakus priest, you can try the deck with 2x blessing for extra reach but you might struggle

Lord Barov replacements?

Lord Barov I would advise crafting, solid craft and fairly essential to the deck - but you can try replacing him with any anti-aggro card, such as devout pupil

Probably too late but for warrior it's definitely worth crafting but I don't think its the same for Paladin, and certainly not this deck, as you can't as reliably get it go off the same turn it's played. Most of the time its anti-synergy with your own big minions.

The purpose of Lord Barov is for board clear so I'd suggest Wild Pyromancer - insane synergy with 0 mana spells and Libram of Justice. 

My version of Libram Pally - more exciting in my humble opinion :)

Which cards can I change?

Polkelt can potentially be replaced with some sort of card draw, abbess is a very powerful highroll card but she isnt essential to the deck, you can try replacing her with another steed, blessing of authority or a devout pupil. The other epics and legends are mostly needed, but if you find you arent facing many control decks you can potentially cut 1 of the 7 costs.

Thanks