That's right and correct.
But I see some difference between 
the two 
phrases : КАК я могу вам помочь? and ЧЕМ я могу вам помочь?
I must say that that's my own opinion and one can have his own point, but I really see the difference. Look : 
I ask ЧЕМ я могу вам помочь? when I really do not know 
what people may wish - they might ASK me where to find 
something, or in 
a situation (when I am Mr Bean and you came 
into the Reception in 
a Hotel) like above 
then ЧЕМ я могу вам помочь? is the duty phrase and means that I am ABLE to do ANYTHING and EVERYTHING you could wish or ask me. 
Now КАК я могу вам помочь? 
I see what in particular is happening at the moment - I understand the problem and ask HOW or with what kind of HELP can I help you. Some woman came from shopping from butic (boutiques?), she came 
in a taxi, the driver helped her to take out all her bags and she 
simply did not know how to pick up TWENTY bags and ribboned boxes with two hands. Then I come to her and ask dirrectly КАК я могу вам помочь?
You see I know that I must take some 
of her bags and help her bring them to her room. But PERHAPS she want to bring some valuable bags herself and tell me 
what BAGS in particular I should take to help her.
If 
i asked her ЧЕМ я могу вам помочь? 
Then she'd answer Help me with 
these bags!! Doesn't he see all my bags??!!
If I ask  КАК я могу вам помочь? she answer take please those ten bags and bring 
them to my room please! 
GOD I made a bunch of mistakes here writing all that and ask 
you to excuse my English, I also hope it 
makes sense. 
 
  
 
Anyway BOTH phrases are FAIR in 
the same situation but I still feel the difference.
 :P  
