First of all, I don't like the way you stated this question. But to the subject:

From 1930 until 1933, the Weimar Republic was governed by "Presidential Cabinets" which meant that Hindenburg, the president ("Reichspräsident") could chose a chancelor and govern without a parlamentary majority. He was allowed to do this due to article 48 which granted him the right to govern with emergency decrees ("Notverordnungen"). The reason was that the policial system was in a state of distress due to the effects of the Great Depression. The large parties couldn't get majorities anymore and the peripheral parties gained a lot of votes.

Hindenburg was pressured to chose Hitler on January 30 1933 as his fourth chancelor, an event which was called "Machtergreifung" in Nazi propaganda and is now called "Machtübertragung" (takeover vs. transfer of power). Note that this was the time of heavy clashes in the streets and a period of great unrest. Hindenburg and influential industrialists behind him thought that they could "tame" Hitler by granting him a degree of power, yet still keeping him away from actual decision making, a plan which failed quite remarkably.

Hitler then used the "Reichstagsbrand" (which is still not entirely resolved... was it laid by Marinus van der Lubbe or the Nazis?) on February 27th in order to confine the basic rights and arrest and murder dissidents, mainly social democrats and communists.

On March 24th Hitler pressured the parliament to consent to the enabling act "Ermächtigungsgesetz" which was basically the step into the Nazi tyranny. It allowed Hitler to pass laws which violated the constitution and dissolved the separation of powers, granting the NSDAP unique authority.

I used to be an encyclopedia on this subject, but it's been a while for me. I hope I managed to sketch the basic outlines for you. There is a great deal of literaturure about the subject, if you're interested. Edit: spelling.