WW1 changed the position of the LIberal Party significantly because of many factors. One major change would have been Asquith stepping down as leader. This was because he was seen as not being able to lead the war, the public disliked the way in his methods with events such as the Shell crisis which led to thousands of unneeded deaths. This was were Lloyd George took over as he was seen fit to lead this war, or control the many issues which Asquith and his former War representative Kitchener could not.
Another was the coalition of the Liberals and the Conservative parties in May 1915. This occurred because during the war, all efforts had to channeled towards that, and so the two leading parties formed this coalition in order to hold off another election. This enabled both leader to stay in power, up until LG took over power from Asquiths poor war effort.
However the war provided some continuity to the political aspects. It put LG into a good a light, he was seen as “the man who won the war”. This allowed LG to run as leader of the coalition in the December 1918 election after the war. The conservatives allowed the LIberals to retain their influence mainly because they didn't think they could compete with such an icon figure in the eyes of the public.
What also changed was the position of the Liberal party. Before the war they were the leading party after very quickly rising above the once leading conservatives. During this war when the conservative popularity began rising and there was minimal seats to split the party and this allowed for the coalition and in turn allowed both Asquith and LG to stay in power.
In conclusion i think WW1 changed the Liberal Party significantly with its coalition, change in leaders and its political power which had changed as a result.