Munich Helles is a beer style that requires considerable exactness in brewing techniques, but it's not "rocket surgery" (Sorry, inside joke from another thread). I can give you some info from memory...
A good simple recipe is 90% Pilsner malt, 10% CaraPils. You could exchange a few percent of the Pilsner for Munich to add a little color and a touch more of maltiness. Your target OG is 1.045-1.051, depending on how much ABV you want. Try to get German malts if you can, but at minimum, Continental. You can mash a number of ways, but I've had good results with a single decoction. Mash-in at 131dF, let sit for 5 minutes, pull 1/3 of the mash (thick) and bring this decoction to 154dF for 10 minutes, then to boiling for 5 min. Return it to the mash tun and this will bring the whole mash up to 154dF. In reference to pulling "1/3" of the mash... you'll want to use some good software to calculate exactly how much to pull. Beersmith has a "Single Decoction" mash setting and has been dead on for me for temps. Whichever way you mash, you want the end product to be delicately malty and flavorful, but fairly dry (1.008-1.012). This is hard to achieve with a single infusion mash.
For hops, your target IBUs are 16 to 22. I haven't had Spaten in a while, but from memory it's probably somewhere between 19 and 22. Any of the German Noble hops are good... any Hallertauer, maybe mix in a little Tettnang. You really only need bittering hops, regardless of what some recipes call for. As a matter of fact, if I was doing it as a single infusion, I definitely wouldn't add anything other than bittering hops, so the malt flavor would be more noticable. However, that being said, I did a single decoction Helles recently that was very malty, but the bitterness seemed fine. So I added a tiny amount of aroma hops at the end of the boil on my next batch. You definitely don't want to add flavoring hops to a Helles. At that point, it starts to become a German Pilsner. When the style guide says "slight hop flavor" is acceptable, this is really carried through from the bittering hops.
Do a 90-minute boil, but don't add bittering hops until 60-minutes. Cool down as fast as you can to as low as you can. You want it below 55dF before you pitch.
For yeast, any of the Bavarian/Munich/German Lager yeasts are good. I've used WLP830 and 838 with good results. The 838 seemed a little more malty. You'll need a big starter... like 3-4 quarts per 5-6 gallons. You can get by with 2 quarts per 5 gallons if you dump the whole thing in, instead of decanting. It's best to start making this a week ahead of brewday, so you can step it up every day or two.
I would ferment in the low end of the optimum temps, like 50dF, maybe even lower, like 48dF. You want this beer as clean as possible... no esters or diacetyl. My typical fermentation schedule for this beer is 2 weeks primary, 4 weeks lagering (at 33dF), then bottle. I almost always do a diacetyl rest just to clean it up. Just be careful not to raise or lower temps by more than 5dF per day so the yeast aren't shocked.
This may not get you a Spaten clone, but it will be a damn good Helles. Did I miss anything? Let me know if you need any more info as this is one of my favorite styles.