Based on Dienekes' instructions, I have created DIYHarappaWorld for anyone to compute their admixture results for my HarappaWorld calculator.

Here's what you need to do:

1. Download DIYHarappaWorld files and unzip them.
2. Download DIYDodecad v2.1 (File->Download).
3. Unpack DIYDodecad2.1.rar by using 7-zip, WinRAR, or Linux rar/unrar command.
4. Start R and change the working directory to where you have the DIY files.
5. Enter the following command in R:

   source('standardize.r')

6. If you have your 23andme raw data, run the following command in R:

   standardize('genome_john_doe.txt', company='23andMe')

   where genome_john_doe.txt is the filename for your raw data file.

7. If you have your FTDNA Family Finder data in a file named johndoe.csv, run the following in R:

   standardize('johndoe.csv', company='ftdna')

8. From your operating system command prompt, run the appropriate command:

   DIYDodecadWin harappaworld.par
   ./DIYDodecadLinux32 harappaworld.par
   ./DIYDodecadLinux64 harappaworld.par

9. The program will start computing the admixture percentages. It took about 5-10 minutes on my computer.
10. The best way to understand your results is to compare them with other populations and individuals. Do not take the component names seriously. They do not represent true ancestral populations.

You can also edit the harappaworld.par file's last line to one of genomewide/bychr/byseg/target to calculate the admixture percentages for the whole genome, by chromosome, by segment or target region respectively. Do note that the last three will have larger noise.

UPDATE: I should also point out that this DIY calculator will work better for those individuals whose genetic variation was included in computing the admixture model. Those belonging to a group not included at all in the set of samples I used might get somewhat odd results.