How to play against the slav defence?

move the right pieces to the right places

Here's your answer (copy and paste or click the URL below):

https://chess4less.com/products/pre-order-cheparinovs-1d4-volume-2-the-slav-semi-slav-ivan-cheparinov?_pos=5&_sid=5f0ba4574&_ss=r

I made a series of videos on this topic! (shameless plug) My pet line vs the Slav has been for a while to take on d5 and play Bg5 and so I talked about how to play that and why it's brought me pretty good results. Complete Anti-Slav Repertoire For White (3. cxd5 cxd5 4. Bg5) - YouTube

BUT I won't pretend like it's the most critical line or the very best (I even show in the first video what I think black should do to achieve rough equality). I think there are a lot of other choices that could easily work for you - this is just the one that helped me get to NM and worked for me in my tournament practice.

Some other pet lines I'm somewhat fond of include 3. Nf3 Nf6 4. Qc2/Qb3/Nbd2 type moves (as played by Shakh a lot) and also you could look at some move orders like 3. Nc3 Nf6 4. e3 (kinda inconveniencing "Classical Slav" players), although you'd still have to deal with mainline Semi-Slavs at some point or another. And of course taking it on with just Nf3/Nc3 and slowly learning the mainlines is a valid option as always.

Finally, you could even play a different move one, such as 1. Nf3 or 1. c4 and get some sort of Slav-like position, say 1. Nf3 d5 2. e3 Nf6 3. c4 c6 4. Nc3. Tons of options

So do some research and find what interests you. Those are just some of my suggestions.

d4 d5 c4 c6 cxd4 cxd4 (exchange slav) Bf4 and you can play it like a london. Nc3 and Nf3 to develop. There is potential Nb5-c7 ideas. Also if Black ever plays Bf5 , then Qb3 can be strong.

If you are looking for something more exciting, paleface attack (f3-e4 idea) against Slav can be fun in blitz.