Problem with PCA

I have an exercise. With 3 kinds of yohourt a,b,c. There are 25
participatients estimate 3 norms: taste (va,vb,vc), structure (ca,cb,cc) and
price (ga,gb,gc) and give the mark from 1 to 5. I don't know how to PCA this
data. Please help me!
I attached the data file follow:
Va	Vb	Vc	Ca	Cb	Cc	Ga	Gb	Gc
4	2	4	5	5	5	4	4	2
2	2	4	3	2	5	4	5	1
2	2	1	2	3	3	3	1	4
1	1	2	2	3	3	4	3	2
3	4	4	4	3	1	2	1	2
1	1	1	1	2	4	3	2	4
4	4	2	2	2	1	2	1	3
2	3	3	3	4	3	1	1	1
4	5	1	3	3	2	4	2	4
2	2	5	1	1	3	2	3	3
4	2	4	5	3	3	4	4	4
3	4	2	1	2	2	1	2	4
1	2	1	2	3	3	3	1	4
3	4	1	1	2	1	2	3	3
5	4	3	4	3	1	1	1	2
4	4	2	2	2	1	4	2	4
2	2	1	1	2	4	3	2	4
3	1	3	4	2	5	3	4	1
1	1	2	2	3	3	4	3	2
2	3	4	3	4	4	4	3	1
2	3	3	3	4	3	1	1	1
4	3	1	1	1	2	2	3	3
1	1	1	1	2	4	3	2	4
3	4	2	1	2	2	3	1	3
3	4	2	1	2	2	1	2	4
 
  

This is a homework problem.  I know how to do a PCA, you need to learn.
 I suggest you visit your textbook, then check the documentation for R's
 various PCA implementations to work out how to effect the analysis.