HOW TO GO FROM LUBLIN TO NALECZOW:

It is easy to go by bus departing from the Lublin main bus station (Al. Tysiąclecia 6) and also from dworzec BUS (for microbuses) very near - when you pass main bus station ticket office and regular bus stops there is another smaller area with stops for microbuses (go to the direction of the church (cerkiew) there will be small stop no 6.
http://www.naleczow.com.pl/informator/kom_busy_lub.html

If you are in Lublin you can take a Taxi for 120 PLN Below are phone numbers:
+48 81 524 00 00
+48 81 444 44 44

HOW TO GO FROM WARSAW TO LUBLIN:

You can come from Warsaw airport to Lublin using Contbus (microbus directly from the airport) for 45 PLN. You can buy tickets from driver or online
https://bilety.contbus.pl/KupBilet.aspx
Eventually, you can go to the city center using bus 175 or local SKM train to the main train station (Warszawa Centralna, aleje Jerozolimskie) but train to Lublin will take a long time because of some repairs of tracks...

HOW TO GO FROM WARSAW TO NAŁĘCZÓW:

Trip by train to Nałeczów will take some time. One part of the route (Dęblin to Nałęczów) is provided by secondary transport due to construction works.
http://www.rozklad.plp

The better option are buses also departing near main train station:
-Contbus (in the front of Marriott hotel (Al. Jerozolimskie 65/79, 00-697 Warszawa)
-Polski Bus (more comfortable and usually cheaper but you need to buy tickets online) (stop at parking area in the front of "Palac Kultury i Nauki (PKiN), Plac Defilad)
https://booking.polskibus.com/Pricing/ShowResults?SID=3m1a0p 1s58013857980lix0dtps&CS=5891646

For Warsaw city bus and SKM you can buy tickets for cc. 5 PLN, in the tickets machine with credit card or coins).
There is also information point in the Warsaw airport when you can get some maps and Warsaw transportation advices.
Then, I would suggest you to come to Warsaw on 6th Dec from Lublin and spend the night before you departure in Warsaw.
You can find more bus connections on:
https://www.e-podroznik.pl

I hope you find avove information useful.