Press the button on the side of the battery and pull:
https://www.amazon.com/s/?ie=UTF8&keywords=makita+1434+battery+replacement&tag=googhydr-20&index=aps&hvadid=181929002846&hvpos=1t1&hvnetw=g&hvrand=6846464313161922942&hvpone=&hvptwo=&hvqmt=b&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9028549&hvtargid=kwd-26585161049&ref=pd_sl_6mj5hck4vs_b_p20