Welp, you want to pitch about twice the amount of yeast you would in an ale. So you’ll have to build up a pitch in some way. Once you have a large enough pitch of healthy, active yeast, you’ll also need VERY precise temp control.
I haven’t done a lager without a digital thermostat monitoring the fermentation temp (NOT THE AMBIENT TEMP), but I can’t imagine you would have much luck if you don’t. Having precise temp control makes doing a diacetyl rest after 11 days much easier, too. I bring it up to 60F over the course of three days, let it rest for a day or two at 60f, and then slowly bring it back down to the temp I get at, which is about 42F.
You’ll also need to aerate well. A lager will easily underattenuate if you do not give it enough o2.
If you’ve done well, it should taste quite fine right out of the fermenter after 2-3 weeks. A month or two of aging in the keg at as cold as you can will certainly help.
I’ve made some great lagers with my methods. I’m sure other’s methods work well, too, but to be honest, apart from pitching more yeast and a different fermenation temp regime, I really don’t do much different when making a lager. It’s all about babying the yeast.