Getting to Dewa Sanzan from Yamagata City

Hi!

I'm currently in Yamagata City and want to go to visit Dewa Santana at some point in the next week.

I was just wondering what the cheapest way to get to Dewa Santana, ideally do the hike in a day and then return to Yamagata would be?

In an ideal scenario I would go straight to the start of the trail from yamagata and I wouldn't stay any nights in Tsuruoka or surrounding places but I'm not sure how viable that would be? (Especially as it not sure if there is a way to get from the end of the trail at Yudonosan back to yamagata).

Any advice or help is welcome!
Thank you :)

There is two tourist information office on the second floor of JR Yamagata station.
It is near the ticket gate so you can easily find it.
http://www.jreast.co.jp/e/stations/e1600.html
http://www.tohokukanko.jp/yamagata/12996/
http://livedoor.blogimg.jp/chirauradayori/imgs/a/b/ab534263.jpg
Also in 1F of a skyscraper located on the west side of the Yamagata station.
http://www.kankou.yamagata.yamagata.jp/db/cgi-bin/search/search.cgi?pa...
http://yamagatakanko.com/acc/
(about 3 min walk fr JR ticket gate 2F, that billding name is "霞城セントラル/Kajo-Central")
https://youtu.be/AIrOoBh3WMk

(small tips about rail station and this billding)
Bike rent is "無料/free". (very rare case as in big cities)
http://www.kankou.yamagata.yamagata.jp/db/cgi-bin/search/search.cgi?pa...
Billding top floor(24F) is "free" observation space (without chair)
and you can out(half open air passage) only in daytime.
http://nightview.useless-landscape.com/details/kajo-central/
https://youtu.be/vPbGUJMPGx4