SMD resistors and capacitors may look similar, but a big difference is that capacitors almost never have their capacitance printed on them, while resistors always have their resistance value on them. So that should tell you whether it's a resistor or capacitor. (Also, most resistors are black, and capacitors beige.)
If it's a resistor the 3 digits printed on it represent its resistance value; the first two digits are the significant digits, while the third indicates the power of ten for the multiplier, i.e. the number of zeros following. In the given picture is shows
104, meaning 10 \$\times\$ 10\$^4\Omega\$ = 100k\$\Omega\$.
You can always safely replace a given size resistor with a larger one (same resistance, of course), since the larger version will be able to dissipate at least as much power as the smaller one. (In this case \$-\$ low voltage + very high resistance \$-\$ it would be even safe to use a smaller resistor, but you made clear that that's not an option.)
I just wanted to add about soldering SMDs when I read Russell's answer. Russell always has good and detailed answers, but this time I don't quite agree with his choice of tweezers. I use Erem 102ACA tweezers, which are not pointed, but have the following tip:
(the visible part is in reality a bit less than 20mm long.)
I find them to give me better control than needle shaped tweezers and I can even solder 0402s with them. (disclaimer: I consider myself clumsy)
If you have a good pair of tweezers and a fine tip temperature controller soldering iron you may have more success soldering an SMD part than a much bigger leaded part, particularly an 0805 should give you little trouble.